{"id":55920,"date":"2024-03-20T11:24:42","date_gmt":"2024-03-20T11:24:42","guid":{"rendered":"https:\/\/biomedpharmajournal.org\/?p=55920"},"modified":"2024-04-01T19:16:27","modified_gmt":"2024-04-01T19:16:27","slug":"small-interfering-rna-drug-delivery-system-in-cancer","status":"publish","type":"post","link":"https:\/\/biomedpharmajournal.org\/staging\/vol17no1\/small-interfering-rna-drug-delivery-system-in-cancer\/","title":{"rendered":"Small Interfering RNA Drug Delivery System in Cancer"},"content":{"rendered":"\n

Introduction<\/strong><\/p>\n\n\n\n

Small interfering\nRNAs (siRNAs) are becoming increasingly used as sequence-specific transcription\ninhibitors. When siRNAs, or short RNAs (double-stranded), are targeted on the\ncells, they mediate gene silencing of protein post-transcriptional phase with a\ndefinite target by destroying messenger RNAs (mRNAs) with matching sequences1,2<\/sup>.\nIt is possible to target any disease-causing gene, as well as any cell type or\ntissue. RNA interference (RNAi), a naturally occurring mechanism that regulates\ngene expression, has emerged as a powerful tool for modifying gene expression\nin a variety of domains, including functional genomics, drug validation, and\ntransgenic design3,4<\/sup><\/p>\n\n\n\n

The RNAi mechanism\nwas primarily discovered in plants and then proven in the Caenorhabditis\nelegans roundworm using a microinjection approach to deliver dsRNA. In C.\nelegans, the introduction of dsRNA molecules can cause intrusive activity and\nvery accurately inhibit complementary gene expression. Inhibition of\ncomplementary gene expression5<\/sup>.Recent research has shed light on the\nmolecular approach of RNAi, In which dsRNA causes homologous mRNA to be\nsilenced. Dicer, an enzyme found in the cytoplasm of mammalian cells, crafts\nRNA silencing which breaks down long dsRNA to produce small interfering RNA\n(siRNA) with a length of 21\u201323 nucleotides. The siRNAs are then integrated into\nan RNA-induced silencing complex (RISC) and unraveled into single-stranded RNA\n(ssRNA), with the sense strand ssRNA then degraded6<\/sup>.<\/p>\n\n\n\n

The antisense strand\nof the RISC then binds to compatible mRNA molecules. The Argonaute 2 protein,\nwhich is a protein of the Argonaute family and is the reason for mRNA\ndegradation and ssRNA synthesis, is one of the primary components of the RISC\ncomplex.7<\/sup><\/p>\n\n\n\n

Argonaute 2 (formerly\nknown as eIF2C2), a catalytic engine inside RISC, allows the anti-sense strand\nof RNA to complement mRNA sequences and damages target mRNAs via the PIWI\ndomain of an Ago protein, which is a structural homolog of RNase H. Although\nAdenosine 5\u2032-triphosphate boosts endonuclease activity, this reaction is not\nessential for the RISC aimed breakdown. The hydrolysis mechanism that releases\nthe 5′-PO4 and 3′-OH groups from the target mRNA phosphodiester backbone\nrequires a divalent metal ion (Mg2+)8-12<\/sup>.<\/p>\n\n\n\n

Mechanisms and Potential Applications of RNAi<\/strong><\/strong><\/p>\n\n\n\n

siRNAs are dsRNAs with a short stretch (19\u201330 nucleotides) that can degrade complementary mRNA in the cytoplasm. Long dsRNAs are cleaved into short dsRNA duplexes or siRNA in the cytoplasm by the endoribonuclease Dicer. RNA-induced silencing complexes are loaded with siRNA (RISC). Argonaute 2 (Ago-2) is a protein that cuts and discharges one strand of double-strand RNA, resulting be an initiated form of RISC with an RNA which is single-strand acts as guide siRNA that guides the selectivity of target mRNA recognition by corresponding base pairing13<\/sup>.The target mRNA is then cleaved between bases 10 and 11 relative to the 5\u2032 end of the siRNA antisense strand, resulting in mRNA degradation and gene silence14<\/sup>.. <\/p>\n\n\n\n\n\n
\"\"<\/td>\n\n

Figure 1:<\/strong> Shows the mechanism of gene silencing by siRNA14<\/sup><\/strong><\/p>\n

<\/p>\n

Click here to view Figure<\/a><\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n\n\n

RNAi Therapeutics a Comparison<\/strong><\/p>\n\n\n\n

siRNA, short\nhairpin RNA (shRNA), and micro-RNA (miRNA) are the three kinds of RNAi14<\/sup>.\nMiRNAs are single-stranded noncoding RNAs that are transcribed by RNA\npolymerase II from their genes or introns. After transcription, the main miRNA\nis first made into siRNA, which has advantages over shRNA in terms of\ntransfection efficiency and distribution. In the transfection process the DNA\nin the chromosome need not be dependent on siRNA’s action, but\nshRNA-articulating pDNA needs a properly structured promoter.RNAi functions on\nthe cytoplasm and during its delivery need not be specific in the nucleus, but\nshRNA will act on the nucleus. The quiescent cells which have limited nuclear\nenvelope permeability possess extra tasks later in the mechanism. In cells with\nmodest proliferative activity, shRNA has less transfection activity as compared\nto siRNA15<\/sup>.<\/p>\n\n\n\n

so comparison to\nshRNA, siRNA has a 100-fold smaller molecular weight (19\u201330 bp), which makes it\neasier to distribute and modify. The rest of this article will be about siRNA.<\/p>\n\n\n\n

Assessment of siRNA with other RNAi therapeutic classes<\/strong><\/p>\n\n\n\n

The ability to quickly create sequences for\nvery selective inhibition of the object of concern is one of the key advantages\nof siRNA over small molecule medicines. In addition, siRNA manufacturing is\nquite simple and does not require a cellular manifestation scheme, refolding\nprocedure, or sophisticated protein purification method16<\/sup>.<\/p>\n\n\n\n

Anti-mRNA approaches can be allocated into\nfour classes: Single-stranded antisense oligonucleotides (ODNs) are chemically\nproduced, short single-stranded oligonucleotides that block the translation of\na definite gene by hybridizing to the suitable mRNA by Watson-Crick binding17<\/sup>.\nRibozymes, which are catalytically active RNAs that use transesterification or\nhydrolysis processes to break single-stranded sections of the RNA18, 19<\/sup>,\nare the second and third anti-mRNA techniques, correspondingly17<\/sup>.<\/p>\n\n\n\n

In cell culture and in vivo, the knockdown\neffects of antisense siRNA and ODNs concluded the effectiveness of siRNA. The\nproteins are targeted by siRNA with high specificity at lower doses than the\nantisense ODNs. Gene expression is less by 100-1000 times as compared to ODNs20<\/sup>.<\/p>\n\n\n\n

In human cells, there was a second comparative\nresearch. The potency, maximal potency, duration of action, and sequence\nspecificity of optimized RNase H-dependent ODNs and siRNA-ODN duplexes were\nexamined. With notable exceptions, the activity of RNase H-dependent ODNs\ntargeted to the same locus was frequently correlated with the activity of 80\nsiRNA-ODN duplexes designed to bind to RNA from four different human genes.\nOnly RNase H-dependent ODNs were found to be active when directed against\npre-mRNA targets, whereas siRNAs were not.<\/p>\n\n\n\n

Finally, microRNAs are endogenous, tiny,\ndouble-stranded, noncoding RNA molecules that have been discovered in a variety\nof organisms and viruses. This family of “new” molecules influences\ngene expression and development by being transcribed primarily from introns,\nexons, and intergenic regions. MicroRNAs are typically 20\u201324 nucleotides long\nand interact with partially mismatched sequences in the messengers’ 3\u2032\nuntranslated regions to alter target mRNAs post-transcriptionally. As a result\nof these interactions, target mRNAs are either repressed or destroyed21<\/sup>.<\/p>\n\n\n\n

Hurdles of siRNA Usage<\/strong><\/p>\n\n\n\n

Clinical trials and\nsiRNA<\/strong><\/p>\n\n\n\n

SiRNAs are emerging as new-generation drugs due to their precise and\nstrong RNAi-triggering potential. Several research have backed up siRNA’s\nmedicinal potential. The effectiveness of viral mRNA-targeted siRNA in blocking\ndifferent stages of the HIV lifetime phase has been demonstrated22<\/sup>.<\/p>\n\n\n\n

There was autoimmune hepatitis seen in mice after injecting Fas-specific\nsiRNA liver failure was reduced 23<\/sup>. Several prospective siRNA\ncandidates are currently being tested in clinical trials for macular\ndegeneration, respiratory disorders, and cancer treatment.<\/p>\n\n\n\n

In biopharmaceutical therapy, siRNA treatment has immense potential.  <\/p>\n\n\n\n

Because siRNA affects translation rather than transcription in DNA, RNAi\nmight not intermingle with DNA in the chromosome. Because there is no DNA\ncontact, there are fewer concerns about undesirable gene changes that could\noccur as a result of gene therapy which is DNA-based. Because siRNA interacts\nwith mRNA rather than protein molecules, it can limit the creation of dangerous\nproteins before they are synthesized.<\/p>\n\n\n\n

Another advantage of\nsiRNA as a therapeutic medication is that it can be used to silence a wide\nspectrum of target proteins to cure illnesses 24<\/sup>. Traditional\nchemical drug targets have been restricted to specific types of ion channels,\nenzymes, and receptors. Monoclonal antibodies and cytokines, for example, are\ncurrently used to target moieties that are mostly found in the blood or on the\ncell surface. An RNAi-built drug, on the other hand, can aim at any mRNA of\ninterest, independent of translated protein location on the cell. Furthermore,\na few siRNA strands are required per cell in effective gene silencing25,\n26<\/sup>.<\/p>\n\n\n\n

Hurdles of siRNA Remedy<\/strong><\/p>\n\n\n\n

The siRNAs have significant benefits as potential\nnovel medications, but further research will have to overcome some obstacles.\nThe possibility of an ‘off-target’ impact, which is the inhibition of a gene\nwhose expression should not be targeted because the gene shares partial\nhomology with the siRNA, is one such difficulty. Inadvertently silencing\nnontarget genes can cause challenges with data interpretation and even harm. To\navoid this problem, great consideration should be given to the choice of\neffective siRNAs. In selecting siRNA it has to be taken care of internal\nrepeating sequences, GC content, secondary structure, and base preference in\nsense strand, the length of siRNA should be 19-22 bps ideally. Several siRNA\nfirms offer online design algorithms that take into account secondary structure,\nsiRNA duplex end-stabilities, and mRNA target sequence, at the same time\nreducing the sequence-dependent off-target effects26<\/sup>.<\/p>\n\n\n\n

The latest reading found that substituting a\n2′-O-methyl ribosyl group at position 2 in the guide strand with\ncomplementarity to the siRNA guide could minimize the silence of most\noff-target transcripts Several computer techniques have been developed for forecasting\nthe role by sequence of siRNA. <\/p>\n\n\n\n

Immune stimulation, or the innate immune\nsystem’s detection of a siRNA duplex, is another obstacle to siRNA therapy23,\n24<\/sup>.<\/p>\n\n\n\n

Due to the stimulus that activates innate\nimmune reactions, too much siRNA has been shown to cause nonspecific effects.\nProtein kinase R, a dsRNA sensor, is thought to trigger the immune system.\nsiRNA is identified by toll-like receptors such as (TLR7), TLR8, and TLR927<\/sup>,\nand activation of NF-kB and interferon regulatory factors was discovered to\ngenerate inflammatory cytokines and interferons.TLR3, a viral RNA that is\ndouble-stranded and acts as a sensor, was recently found to be activated by\n21-nucleotide or longer siRNAs, which suppressed neovascularization in a\nsequence and target-nonspecific way28<\/sup>.<\/p>\n\n\n\n

Nevertheless, additional research has found\nthat not all siRNAs can stimulate the immune system29, 30<\/sup>.<\/p>\n\n\n\n

As per the discussion\nby MacLachlan et al siRNA stimulates the immune response which is found to be\nsignificant in nucleotide sequence. It was discovered that induction by siRNA\nby TLR7-mediated interferon alpha is always sequence-specific. As a result, the\nsequencing issue of siRNA-mediated immune activation must be studied further.<\/p>\n\n\n\n

In-vivo Application of siRNA Delivery Systems<\/strong><\/p>\n\n\n\n

Several RNAi vectors\nfor distribution into the cell’s cytoplasm have been reported by researchers\nand biotechnology companies, and while these are adequate for in vitro\napplications, this delivery method is frequently ineffectual in vivo.In\nclinical trials, siRNAs are currently delivered locally to particular target\nlocations such as the lungs and eye, eluding the complexities of systemic\ndistribution. To cure most tumors and other disorders, however, siRNA must be\nadministered systemically.<\/p>\n\n\n\n

The following characteristics\nshould be included in the best siRNA in vivo systemic delivery. First and\nforemost, delivery systems must be biodegradable, biocompatible, and safe for\nthe immune system. Next, the formulation must reach the target site or tissues,\nwhereas it should be an intact strand formulation thereby avoiding serum\nnuclease degradation. Following that, after systemic administration, the\ndelivery systems must provide target tissue-specific distribution to avoid\nrapid hepatic or renal clearance. To end with, the endocytosis has delivered\nsiRNA to target cells; the systems must encourage the endosomal discharge of\nRNAi into the cytoplasm, permitting siRNA to interact with endogenous RNA31<\/sup>.<\/p>\n\n\n\n

Advantages and Drawbacks<\/strong><\/p>\n\n\n\n

Most creatures, from\nplants to vertebrates, have already been shown to be affected by RNA\ninterference. It’s also had a big impact on biomedical research, and it’ll lead\nto some interesting medical applications. Most creatures, from plants to\nvertebrates, have already been shown to be affected by RNA interference. This\nwill light up biomedical research with news on medical applications.\nInfections, cancer, antiviral diseases (e.g., human immunodeficiency virus 1,\nHIV-1and viral hepatitis), neurodegenerative illnesses, and antiviral diseases\n(e.g., human immunodeficiency virus 1, HIV-1 and viral hepatitis) could all\nbenefit from RNAi in the future. RNAi could be a game-changing new treatment\noption for infections, neurodegenerative illnesses, cancer, and antiviral\ndiseases (e.g., human immunodeficiency virus 1, HIV-1, and viral hepatitis),\nunfocused exceptionally profound cell lines study then relatively high doses,\nsiRNAs longer than 30 nucleotides activate the immune system32-35<\/sup>.<\/p>\n\n\n\n

In vivo\u2013administered\nsiRNAs also have poor tissue penetration, low transfection efficiency, and\nnonspecific immune activation, which have hindered their beneficialefficacy.\nHowever, the absence of an effective delivery technique to aim and inject siRNA\ninto the required cells is a significant constraint for this approach’s full\ntherapeutic perspective.<\/p>\n\n\n\n

Scientists are trying\nfor an effective delivery system that can injected and should be compatible\nwith minimal side effects and comfirmly achieve the region or tissue of\ninterest. <\/p>\n\n\n\n

Cancer Therapy of siRNA<\/strong><\/p>\n\n\n\n

The siRNA and RNAi phenomena\nensure innovative possibilities for the improvement of inventive treatments to\ncure earlier incurable ailments, like as cancer. Because it uses the endogenous\nRNAi system, allowing for the careful lessening of disease-associated genetic\nfactors, and can be applied to any gene with a corresponding arrangement, siRNA\nhas intrinsic efficacy36<\/sup>. Many essential genes involved in many\nmalignancies have been learned, the mutations carefully defined, and the trials\nvia the act are categorized since cancer is a genetic illness37<\/sup>.<\/p>\n\n\n\n

The argument for\nsiRNA-mediated gene therapy is supported by the genetic nature of cancer.\nSeveral siRNAs have been engineered to target dominant oncogenes, dysregulated\noncogenes, or viral oncogenes involved in carcinogenesis. Therapeutic siRNAs\nhave also been studied for their ability to silence target molecules important\nfor tumor-host interactions and tumor resistance to chemotherapy. Anti\nproliferative and\/or apoptotic effects have been shown when siRNAs are used to\nturn off key cancer-associated target proteins.<\/p>\n\n\n\n

Nonetheless, the\nmajority of RNAi-mediated gene silencing for cancer therapy has been done in\ncell cultures in the lab, and there are still major roadblocks in the move to\nthe bedside due to delivery issues. It is necessary to design delivery\nstrategies that can improve siRNA stability and cancer cell selectivity while\nminimizing off-target and nonspecific immune stimulatory effects. The\nformulation methods need to be tailored for definite tumors because the method\nof management may vary based on the form of the malignancy.<\/p>\n\n\n\n

Breast Tumour<\/strong><\/p>\n\n\n\n

Breast sarcoma is\ncharacterized by uncontrolled cell growth in breast tissues and ranks as the\nsecond most common cancer worldwide, following lung sarcoma. Among females in\nthe United States, breast cancer is the most frequently diagnosed cancer and a\nleading cause of cancer-related deaths in this population. Surgical\nintervention is the primary treatment for localized breast cancer, with\nadditional options including hormone therapy, chemotherapy, immunotherapy,\nand\/or radiotherapy. Researchers have explored the use of lipid or\npolymer-based delivery systems for anti-cancer siRNA in breast cancer cells and\nmouse models with human breast tumor xenografts38<\/sup>.<\/p>\n\n\n\n

To transport siRNAs\nto breast cancer cell lines, cationic liposomes containing dicta decyl amido\nglycyl spermidine (DOGS) and DOPE were employed. These liposomes showed\nsuccessful delivery of siRNAs and specific localization in cytoplasmic\ncompartments near the nucleus. They exhibited low cytotoxicity and high uptake\nof cyclin D1-specific siRNA in MCF-7 breast cancer cells, as well as efficient\ndelivery of plasminogen activator inhibitor type I-specific siRNA to MDA MB 231\nbreast cancer cells39<\/sup>.<\/p>\n\n\n\n

In another study, a\nhybrid molecule consisting of DNA and RNA, targeting HER-2, was encapsulated in\nimmune cationic liposomes modified with a single-chain anti-transferrin\nreceptor antibody fragment. Intravenous administration of these liposomes in\nmice with MDAMB-435 human breast cancer tumors resulted in suppression of HER-2\nexpression.<\/p>\n\n\n\n

PEI-g-PEG copolymers\nhave been utilized as safe carriers for siRNA targeting the clusterin secretory\nsignal peptide. These complexes effectively inhibited clusterin secretion and\nenhanced the lethality of ionizing radiation in MCF-7 human breast cancer cells40<\/sup>.<\/p>\n\n\n\n

Chitosan\nnanoparticles containing quantum dots were employed to deliver HER2\/neu siRNA.\nThe nanoparticles efficiently entered SKBR3 breast cancer cells, thanks to the\nentrapped fluorescent quantum dots, and achieved precise delivery of siRNA to\nHER2-overexpressing cells, resulting in gene silencing41-43<\/sup>.<\/p>\n\n\n\n

Furthermore,\nself-assembling cationic core-shell nanoparticles composed of biodegradable\namphiphilic copolymers were developed for the co-delivery of small-molecule\nanticancer drugs and siRNA. This approach showed enhanced sensitivity to\npaclitaxel in MDA-MB-231 human breast cancer cells when combined with siRNA\ntargeting Bcl-244<\/sup>.<\/p>\n\n\n\n

In summary, various\ndelivery systems, including liposomes, nanoparticles, and copolymers, have been\ninvestigated for the targeted delivery of siRNA in breast cancer treatment.\nThese approaches offer promising strategies for improving therapeutic outcomes\nin breast cancer patients.<\/p>\n\n\n\n

Ovarian Cancer<\/strong><\/p>\n\n\n\n

Ovarian cancer ranks\nas the eighth most commonly diagnosed cancer in women. It is a particularly\nlethal gynecologic cancer due to challenges in early detection and the limited\neffectiveness of chemotherapy. Although several theories exist, the exact\ncauses of ovarian cancer remain unknown. Treatment options for ovarian cancer\nhave traditionally included surgery, chemotherapy, and radiation therapy.\nHowever, the toxic nature of the tumor has prompted extensive research into in\nvivo siRNA treatments using various synthetic techniques in animal models45<\/sup>.<\/p>\n\n\n\n

In one study,\nlow-molecular-weight linear PEI was utilized to deliver HER-2\nreceptor-targeting siRNA via intraperitoneal administration in mice with\nsubcutaneously xenografted SKOV-3 ovarian cancer cells. The complexation of\nsiRNA with PEI resulted in a significant reduction in tumor growth by\ndownregulating HER-2 expression in the animal model. Notably, this effect was\nobserved with the PEI-complexed siRNA, but not with free siRNA46<\/sup>.<\/p>\n\n\n\n

Sood et al. conducted\na series of ovarian cancer treatment trials involving siRNA-based approaches,\nincluding the use of neutral liposomes. They successfully encapsulated\nEphA2-targeting siRNA within neutral liposomes based on\n1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC) with an encapsulation\nefficiency of 65 percent. In xenografted mouse models of ovarian carcinoma,\nintravenous administration of liposomal EphA2-targeting siRNA at a dosage of\n0.15 mg\/kg inhibited tumor growth. Furthermore, combining siRNA with paclitaxel\nresulted in a significant reduction in ovarian tumor growth in a mouse model.\nThe efficacy of intraperitoneal treatment with liposomal EphA2-targeting siRNA\nin reducing tumor growth in ovarian cancer mouse models was comparable to that\nachieved through intravenous delivery of siRNA liposomes. Other studies using\nneutral DOPC-based liposomes demonstrated the delivery of siRNAs targeting -2\nadrenergic receptor, interleukin-8, and focal-adhesion-kinase, resulting in the\nsuppression of ovarian tumor growth47-50<\/sup>.<\/p>\n\n\n\n

In summary, ovarian\ncancer poses significant challenges, but siRNA-based therapies using various\ndelivery methods such as PEI complexes and liposomes have shown promise in\ninhibiting tumor growth in animal models. These approaches hold the potential\nfor advancing ovarian cancer treatment strategies.<\/p>\n\n\n\n

Lung Cancer<\/strong><\/p>\n\n\n\n

Lung cancer is a\nleading cause of cancer-related mortality in men and the second leading cause\nin women. It can be categorized into small-cell lung carcinoma and\nnon-small-cell lung carcinoma, requiring distinct treatment approaches. Recent\nadvancements in lung cancer therapy have identified molecular targets such as\ngefitinib (Iressa), erlotinib (Tarceva), and bevacizumab, which selectively\ninhibit specific proteins involved in tumor growth and angiogenesis51-52<\/sup>.<\/p>\n\n\n\n

In the context of\nlung cancer, liposomes loaded with human double-minute gene 2-specific siRNA\nwere developed with arginine octamers on their surface. These siRNA-loaded\nliposomes exhibited good stability in the bloodstream and efficiently\ntransfected multiple lung cancer cell lines after 24 hours of incubation53<\/sup>.<\/p>\n\n\n\n

LPD\n(liposome-polycation-DNA) nanoparticles were utilized for RNA interference in\nlung carcinoma. PEGylated LPD nanoparticles containing RNAi targeting survivin\ndemonstrated antitumor effects by promoting apoptosis, suppressing tumor cell\nproliferation, and enhancing the sensitivity of tumor cells to anticancer\ndrugs. In an in vivo lung cancer xenograft mouse model, LPD nanoparticle\nformulations exhibited substantial tumor growth inhibition. Intravenous\nadministration of epidermal growth factor receptor-specific siRNAs using LPD\nnanoparticles, in combination with cisplatin, synergistically suppressed lung\ncancer tumor activity54<\/sup>.<\/p>\n\n\n\n

To enable systemic\ndelivery, cationic immunoliposomes carrying siRNA were employed in an animal\nmodel of lung cancer metastasis. These immunoliposomes, coupled with a\nsingle-chain antibody fragment targeting the transferrin receptor, were\nadministered intravenously to mice. The fluorescently labeled siRNA delivered\nby cationic immunoliposomes specifically accumulated in lung tissues with tumor\nmetastases, while sparing the liver55<\/sup>.<\/p>\n\n\n\n

In summary,\nsiRNA-based therapies using liposomes, LPD nanoparticles, and cationic\nimmunoliposomes have shown promising results in targeting lung cancer. These\ndelivery systems offer efficient transfection, tumor growth inhibition, and\nspecific siRNA distribution, providing potential avenues for the development of\neffective lung cancer treatments.<\/p>\n\n\n\n

Liver Carcinoma <\/strong><\/p>\n\n\n\n

While various factors\ncontribute to the development of liver cancer, infection with hepatitis B virus\n(HBV) or hepatitis C virus (HCV) is considered significant. Surgery, including\nliver transplantation, is the primary treatment option for hepatocellular carcinoma\n(HCC) and large liver tumors. Chemotherapy and radiotherapy can be used as\nadjuvant therapies56<\/sup>.<\/p>\n\n\n\n

Chronic HBV infection\nis known to increase the risk of cirrhosis and HCC, and RNA interference\n(RNAi)-based therapeutics have shown potential in treating HBV infection. In\nanimal models with HBV replication, chemically modified siRNAs targeting HBV\nRNA were administered intravenously. High-dose siRNA treatment at 30 mg\/kg\nresulted in a significant decrease in serum HBV DNA levels, highlighting the importance\nof chemically altered siRNAs for HBV treatment57<\/sup>.<\/p>\n\n\n\n

To improve the\ndelivery of siRNA targeted to HBV RNA, a lipid-based SNALP (stable nucleic\nacid-lipid particle) technology was utilized. SNALP-encapsulated siRNA,\nadministered through three daily intravenous injections at a dose of 3 mg\/kg,\nexhibited an extended half-life in the liver. This led to a substantial 95\npercent reduction in HBV serum titers, with the reduction being dose-dependent\nand sustained for up to 7 days after the final dose. Importantly, SNALP did not\ninduce immune responses or the production of interferon\u2019s or inflammatory\ncytokines58<\/sup>.<\/p>\n\n\n\n

In a liver metastasis\nmodel, a lipid-based system was employed to deliver siRNA in vivo. Liver tumors\nwere induced in nude mice through intrasplenic injection of A549 cell lines.\nAnti-human bcl-2 siRNA was combined with a cationic liposome LIC-101 composed\nof specific lipid components. Intravenous administration of the siRNA and\nLIC-101 complex for two 5-day cycles resulted in significant shrinkage of liver\ntumor nodules. Additionally, the use of LIC-101 facilitated siRNA transport to\nthe liver, unlike bare siRNA59<\/sup>.<\/p>\n\n\n\n

In summary,\nRNAi-based therapies using chemically modified siRNAs and lipid-based delivery\nsystems show promise in the treatment of HBV infection and liver cancer,\noffering potential advancements in therapeutic approaches.<\/p>\n\n\n\n

Prostate Cancer<\/strong><\/p>\n\n\n\n

Prostate cancer ranks\namong the most prevalent malignancies in men in the United States, and it is\nthe third leading cause of cancer-related death among males. Due to its high\nincidence, there is a critical need for the development of new therapeutic\napproaches. Clinical studies are currently underway to evaluate the efficacy of\nnovel treatments such as kinase inhibitors, antisense oligonucleotides, and\nheat shock protein inhibitors for prostate cancer60<\/sup>.<\/p>\n\n\n\n

In animal models,\ncationic liposomes have been utilized to deliver various RNAi therapies for\nprostate tumor treatment. One study conducted by Pal et al. employed\ncardiolipin liposomes as a delivery system for siRNA targeting Raf-1. The siRNA\ncomplexed with cardiolipin liposomes was administered intravenously in a mouse\nxenograft model of human prostate cancer. This treatment effectively inhibited\ntumor progression by targeting Raf-1 expression within the tumor tissue61<\/sup>.<\/p>\n\n\n\n

Another study by\nBisanz et al. demonstrated the therapeutic effect of cationic liposome\u2019s\ncontaining dipalmitoyl ethyl phosphocholine, dioleoyl phosphoethanolamine,\ndipalmitoyl phosphoethanolamine, and polyethylene glycol, which were used to\ndeliver integrin alphaV-specific siRNA. Intratumoral administration of\nanti-integrin alpha V siRNA and liposomes effectively suppressed tumor growth\nin xenograft models of human PC3 prostate cancer cells grown in the flank and\ntibia62<\/sup>.<\/p>\n\n\n\n

Furthermore, cationic\nliposome\u2019s comprising AtuFECT01,\n1,2-diphytanoyl-sn-glycero-3-phosphoethanolamine, and DSPE-PEG were used to\ncomplex CD31 siRNA, which selectively targets endothelial cells. In rats with\nprostate tumors, intravenous administration of anti-CD31 siRNA lipoplexes\nresulted in reduced tumor growth and metastases63<\/sup>.<\/p>\n\n\n\n

In a different\napproach, subcutaneous injection of LIC-101 cationic liposomal anti-bcl-2 siRNA\neffectively reduced tumor size in mice with subcutaneously xenografted prostate\ncancer (PC-3) cells.<\/p>\n\n\n\n

Overall, these\nstudies highlight the potential of cationic liposomes as delivery systems for\nsiRNA-based therapies in prostate cancer treatment, demonstrating promising\nresults in animal models64<\/sup>.<\/p>\n\n\n\n

Others<\/strong><\/p>\n\n\n\n

Numerous alternative\ndelivery techniques have been explored for targeted delivery to cancer tissues,\nincluding cationic liposomes, polymers, inorganic nanoparticles, and\nantibody-based systems. In vivo, assessments of siRNA-mediated RNA interference\neffects have frequently been conducted in mice using subcutaneous xenograft\nmodels. SiRNAs have been administered intratumorally or intravenously using\nvarious delivery systems to target diseases such as brain cancer, glioblastoma,\nnasopharyngeal cancer, gastric cancer, and prostate cancer. Efficient delivery\nof siRNA to the brain has posed challenges due to the limited transport of\nsiRNA across the blood-brain barrier. However, a recent advancement utilized a\nreceptor-specific monoclonal antibody delivery technique coupled with\navidin-biotin interaction to successfully deliver siRNA to brain cancer models\nin vivo65<\/sup>.<\/p>\n\n\n\n

In this approach,\nmono-botinylated siRNA specific to luciferase was linked to a combination of\nstreptavidin and an anti-transferrin receptor monoclonal antibody. Intravenous\nadministration of the biotinylated siRNA at a dose of 0.27 mg\/kg in animals\nwith intracranial luciferase-producing glial cell tumors resulted in a\nsubstantial reduction (69-81%) in luciferase gene expression within the\nintracranial brain tumors. Another study employed siRNA complexed with PEI\nspecifically targeting the secreted growth factor pleiotrophin (PTN) for\nintracerebral therapy. This approach demonstrated reduced tumor growth and cell\nproliferation in an orthotopic glioma mouse model without any reported toxicity\nor abnormal behavior in the animals66<\/sup>.<\/p>\n\n\n\n

Different delivery\nsystems of siRNA for cancer treatment are shown in Table 1<\/p>\n\n\n\n

Table 1: SiRNA delivery system for treatment of cancer67-92<\/sup>.<\/strong><\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\n

Delivery system <\/strong><\/p>\n<\/td>\n

\n

Property <\/strong><\/p>\n<\/td>\n

\n

Target gene <\/strong><\/p>\n<\/td>\n

\n

Animal model <\/strong><\/p>\n<\/td>\n

\n

Route <\/strong><\/p>\n<\/td>\n<\/tr>\n

\n

liposomes<\/p>\n<\/td>\n

\n

SNALP<\/p>\n<\/td>\n

\n

HBV<\/p>\n<\/td>\n

\n

HRV vector Based mouse<\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Cationic liposome<\/p>\n<\/td>\n

\n

Bcl-2<\/p>\n<\/td>\n

\n

Liver metastasis mouse model <\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Cationic liposome<\/p>\n<\/td>\n

\n

Integrin<\/p>\n<\/td>\n

\n

Prostate cancer xenograft<\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Cationic liposome<\/p>\n<\/td>\n

\n

CD31<\/p>\n<\/td>\n

\n

Prostate cancer xenograft<\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Cationic liposome<\/p>\n<\/td>\n

\n

Bcl-2<\/p>\n<\/td>\n

\n

Prostate cancer xenograft<\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Cationic cardiolipin liposome<\/p>\n<\/td>\n

\n

Raf-1<\/p>\n<\/td>\n

\n

Prostate cancer xenograft<\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Cationic cardiolipin analogue-based liposomes<\/p>\n<\/td>\n

\n

c-raf<\/p>\n<\/td>\n

\n

Breast cancer xenograft<\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Neutral liposomes (DOPC)<\/p>\n<\/td>\n

\n

EphA2<\/p>\n<\/td>\n

\n

Ovarian cancer xenograft<\/p>\n<\/td>\n

\n

i.v\/i.p<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Neutral liposomes (DOPC)<\/p>\n<\/td>\n

\n

FAK<\/p>\n<\/td>\n

\n

Ovarian cancer xenograft<\/p>\n<\/td>\n

\n

i.p<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Neutral liposomes (DOPC)<\/p>\n<\/td>\n

\n

ADRB2<\/p>\n<\/td>\n

\n

Ovarian cancer xenograft<\/p>\n<\/td>\n

\n

i.p<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Neutral liposomes (DOPC)<\/p>\n<\/td>\n

\n

IL-8<\/p>\n<\/td>\n

\n

Ovarian cancer xenograft<\/p>\n<\/td>\n

\n

i.p<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Liposome-polycation-DNA<\/p>\n<\/td>\n

\n

EGFR<\/p>\n<\/td>\n

\n

Lung cancer xenograft<\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Cationic<\/p>\n

immunoliposome<\/p>\n<\/td>\n

\n

 <\/p>\n<\/td>\n

\n

Lung metastasis <\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Immunoliposome<\/p>\n<\/td>\n

\n

Her-2<\/p>\n<\/td>\n

\n

Breast cancer xenograft<\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

Nanoparticles<\/p>\n<\/td>\n

\n

Caco3<\/sub> nanoparticle<\/p>\n<\/td>\n

\n

VEGF<\/p>\n<\/td>\n

\n

Gastric cancer xenograft<\/p>\n<\/td>\n

\n

i.t<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Chitosan-coated nanoparticles<\/p>\n<\/td>\n

\n

RhoA<\/p>\n<\/td>\n

\n

Breast cancer xenograft<\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Folated lipid nanoparticle<\/p>\n<\/td>\n

\n

Her-2<\/p>\n<\/td>\n

\n

Nasopharyngeal cancer xenograft<\/p>\n<\/td>\n

\n

i.t<\/p>\n<\/td>\n<\/tr>\n

\n

Polymers<\/p>\n<\/td>\n

\n

PEI<\/p>\n<\/td>\n

\n

Her-2<\/p>\n<\/td>\n

\n

Ovarian cancer xenograft<\/p>\n<\/td>\n

\n

i.p<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

PEI<\/p>\n<\/td>\n

\n

PTN<\/p>\n<\/td>\n

\n

Orthotopic gliobastoma<\/p>\n<\/td>\n

\n

i.c<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Poly (ester amine)<\/p>\n<\/td>\n

\n

AKT1<\/p>\n<\/td>\n

\n

Urethane induced lung cancer<\/p>\n<\/td>\n

\n

Inhalation<\/p>\n<\/td>\n<\/tr>\n

\n

Others<\/p>\n<\/td>\n

\n

Atelocollagen<\/p>\n<\/td>\n

\n

HPV<\/p>\n<\/td>\n

\n

cervical cancer xenograft<\/p>\n<\/td>\n

\n

i.t<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Chemical Modification<\/p>\n<\/td>\n

\n

HBV<\/p>\n<\/td>\n

\n

HRV vector.based mouse<\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Carbon nanotube<\/p>\n<\/td>\n

\n

TERT<\/p>\n<\/td>\n

\n

Lewis lung Tumor<\/p>\n<\/td>\n

\n

i.t<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Cyclodextrin containing polycation<\/p>\n<\/td>\n

\n

EWS-FLII<\/p>\n<\/td>\n

\n

Metastatic ewings sarcoma<\/p>\n<\/td>\n

\n

i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Fusion protein<\/p>\n<\/td>\n

\n

c-myc, MDM2, VEGF<\/p>\n<\/td>\n

\n

Subcutaneous B16 Melanoma Tumor<\/p>\n<\/td>\n

\n

i.t\/i.v<\/p>\n<\/td>\n<\/tr>\n

\n

 <\/p>\n<\/td>\n

\n

Electroporation<\/p>\n<\/td>\n

\n

EGFP<\/p>\n<\/td>\n

\n

Subcutaneous B16F10 expressing ECFP<\/p>\n<\/td>\n

\n

i.t<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

i.v= intravenous injection, i.p = intraperitoneal injection, i.t intratumoral injection, i.c = intracerebral injection<\/p>\n\n\n

Design and Synthesis of Target-Specific siRNAs<\/strong><\/p>\n\n\n\n

The selection of siRNAs specific to mRNA is a\ncrucial step in designing effective RNA interference (RNAi) strategies for\ntargeting specific genes. Despite the existence of numerous algorithms for\nsiRNA selection, many of them are inefficient, lack transparency, or have\ncommercial restrictions93<\/sup>.To address this, a study introduced an\nopen-source JAVA tool that accurately predicts active siRNAs, with a Pearson\ncorrelation coefficient of 0.52 based on a dataset of 526 siRNAs. The release\nof version 1.0 of this tool also allows for community contributions to further\nimprove the open-source code94<\/sup>.<\/p>\n\n\n\n

In conventional siRNA design, the initial step\ninvolves identifying coding sequences that are devoid of translational or\nregulatory proteins. Regions approximately 115 bases downstream of the start\ncodon are typically selected. Sequence motifs containing an AA (or NA)\ndinucleotide followed by about 20 bases with a G\/C content ranging from 35% to\n75% are then chosen. The choice of the dinucleotide leader determines the\ncomposition of the antisense 3′ overhangs, resulting in 20-base duplexes\ntargeting AA (N20) having a 3′ termini of UU or dTdT.<\/p>\n\n\n\n

The antisense strand of the siRNA is designed\nto perfectly match the target mRNA sequence. Using traditional methods, 65-75%\nof siRNA duplexes exhibit 50-65% gene silencing efficacy, although the\neffectiveness of gene knockdown may vary. In many cases, gene knockdown levels\nbelow 70% may not have significant physiological or therapeutic relevance. This\nnecessitates the use of additional techniques to enhance the gene-silencing\ncapacity of commonly produced siRNAs.Virus-mediated siRNA delivery for a\nvariety of illnesses95<\/sup>.<\/p>\n\n\n\n

Viral-mediated delivery of siRNA has emerged\nas a promising approach for in vitro and in vivo applications targeting various\ndiseases. Lipid-based delivery reagents often face limitations in successfully\ntransfecting desirable cell types like primary cells or those in the immune\nsystem. In such cases, viral delivery of RNAi cassette-containing vectors has\nbecome a favorable alternative. Viruses possess the ability to infect a wide\nrange of mammalian cell types, including challenging-to-transfect cells,\nprimary cells, and non-dividing cells, making them efficient carriers for gene\ndelivery. Certain viral vectors, such as adenoviruses, can infect both dividing\nand non-dividing cells, and they offer advantages such as high stability of\nrecombinant vectors, large insert capacity, and the ability to be produced at\nhigh titers96<\/sup>.<\/p>\n\n\n\n

Viruses naturally possess the ability to\nefficiently deliver their genetic material into host cells, making them\nattractive candidates for constructing therapeutic gene delivery virus vector\nsystems. Recent advancements have seen the utilization of viral vectors derived\nfrom RNA and DNA viruses with diverse genomic layouts and host preferences in\nboth laboratory research and clinical practice.<\/p>\n\n\n\n

Several viruses have been selected as gene\ndelivery vehicles due to their capability to accommodate foreign genes and\neffectively transfer them, resulting in efficient gene expression97<\/sup>.<\/p>\n\n\n\n

Retroviruses, adenoviruses, adeno-associated\nviruses, herpes viruses, and poxviruses are being extensively used in more than\n60% of clinical gene therapy trials worldwide due to these reasons. For\ninstance, the wild-type adenovirus genome has a length of approximately 35\nkilobases (kb), with the potential to replace up to 30 kb of foreign DNA in the\nviral genome98<\/sup>.<\/p>\n\n\n\n

Some viruses have been chosen as gene delivery\nvehicles because of their capacity to hold foreign genes and their ability to\nsuccessfully transfer these genes, which correlates with efficient gene\nexpression.<\/p>\n\n\n\n

Retroviruses, adenoviruses, adeno-associated\nviruses, herpesviruses, and poxviruses are used in more than 60% of clinical\ngene therapy trials around the world for these reasons99<\/sup>.<\/p>\n\n\n\n

Because recombinant adenovirus lacks key\nreplication genes, infected cells can express the therapeutic gene without\nreplicating the vector100<\/sup>.<\/p>\n\n\n\n

An adenoviral vector that contains a tandem\nsiRNA expression unit. This vector utilizes two human U6 promoters to\ntranscribe the sense and antisense strands of the siRNA duplex separately101-103<\/sup>.\nThe target of this siRNA is survivin, an antiapoptotic molecule that is\ntypically over expressed in cancer cells but not detectable in terminally ill\npatients. This particular adenoviral vector is most suitable for adult tissues\nthat have undergone differentiation. The introduction of Adv-siSurv into HeLa,\nU251, and MCF-7 cancer cells effectively triggered apoptosis and resulted in\nvisible signs of infection. Both in vitro and in vivo experiments showed a\nsignificant reduction in the growth capacity of these cancer cells104<\/sup>.\nIntramuscular injections of Adv-siSurv also demonstrated substantial inhibition\nof tumor growth in a xenograft model, using U251 glioma cells. Another study\nfocused on an adenoviral vector capable of expressing siRNA molecules targeting\np53 or VprBP\/KIAA0800, a cellular protein that interacts with the HIV auxiliary\nprotein viral protein r (Vpr). In all cases, adenoviral infection led to a\nspecific decrease in the target protein level, which correlated with a\nreduction in the corresponding mRNA level. Lentiviruses, similar to\nretroviruses, can infect both dividing and non-dividing cells. Lentiviral\nvectors derived from HIV are well-known in the field, and they can be produced\nat high concentrations of N10^9 virus particles per milliliter. Experimental\ndata demonstrated that when lentiviral vectors were injected into mouse eyes,\nthe transgenic expression persisted for at least 12 weeks without significant\ndecline105<\/sup>.<\/p>\n\n\n\n

Future Prospects<\/strong><\/p>\n\n\n\n

Traditional pharmaceutical medications have\nvarious advantages that siRNA therapies do not. Because siRNAi is an endogenous\nbiological process, siRNA may effectively silence practically any gene. The\ndevelopment of highly selective and inhibitory sequences is much faster than\nthe development of new pharmaceuticals, and synthesizing and manufacturing\nsiRNA on a large scale is quite straightforward106<\/sup>.<\/p>\n\n\n\n

Several oncogenes are related to excessively\nhigh expression in cancers. The use of endogenous RNAi machinery to interfere\nwith specific oncogene expression could lead to the creation of a treatment\nmethod that is effective against a wide range of malignancies.<\/p>\n\n\n\n

Because the RNAi system allows for the precise\nsilence of pathogenic genes or gene targets involved in melanoma development,\nsiRNA-based therapies are an appealing and potent option to treat numerous\ntumors.<\/p>\n\n\n\n

Despite great progress, there are still\nchallenges to overcome in the field of in vivo siRNA administration. Off-target\neffects and immunological activation must be avoided, which necessitates the\ndevelopment of solutions.<\/p>\n\n\n\n

Synthetic systems based on lipids or polymers\nhave recently been proven to produce powerful RNAi effects after systemic\ninjection. After intravenous administration of siRNA utilizing adequate\ndelivery mechanisms, nonhuman primates showed target-specific RNAi effects107,\n108<\/sup>.<\/p>\n\n\n\n

Interpretation of si RNA Formulation<\/p>\n\n\n\n

Precision Medicine: The siRNA drug delivery\nsystem has the potential to revolutionize medicine by offering highly specific\ntreatments tailored to individual patients. Since siRNAs can be designed to\ntarget a particular gene sequence, the therapy can be customized for various\ngenetic mutations, providing more precise and effective treatments.<\/p>\n\n\n\n

Gene Silencing: The core mechanism of the\nsiRNA drug delivery system is gene silencing. By silencing specific genes\ninvolved in disease progression, it is possible to halt or mitigate the harmful\neffects of certain diseases without causing widespread collateral damage to\nhealthy cells and tissues.<\/p>\n\n\n\n

Therapeutic Potential: SiRNA-based therapies\nhold great promise for treating a wide range of diseases that were previously\nconsidered challenging to manage using traditional pharmaceuticals. These\ninclude genetic disorders, neurodegenerative diseases, viral infections, and\ncertain types of cancers.<\/p>\n\n\n\n

Hypothesis<\/p>\n\n\n\n

Enhanced Drug Delivery: One of the critical\nchallenges in siRNA therapy is delivering the siRNA molecules efficiently to\nthe target cells. Hypotheses might explore novel drug delivery systems, such as\nlipid nanoparticles, polymer-based carriers, or viral vectors, that can protect\nand deliver siRNA to the desired tissues with minimal side effects.<\/p>\n\n\n\n

Immune Response and Off-Target Effects: When\nintroducing exogenous siRNA into the body, there is a possibility of triggering\nan immune response or causing unintended effects by targeting genes other than\nthe intended ones. The hypothesis could focus on optimizing siRNA designs or\nexploring ways to minimize these off-target effects.<\/p>\n\n\n\n

Stability and Half-Life: siRNAs are\nsusceptible to degradation by cellular nucleases, which can limit their\ntherapeutic efficacy. Researchers might hypothesize on methods to enhance siRNA\nstability and prolong their half-life within the body for sustained therapeutic\neffects.<\/p>\n\n\n\n

Combination Therapy: To maximize therapeutic\nbenefits, the hypothesis could explore the potential of combining siRNA therapy\nwith other treatment modalities, such as chemotherapy or immunotherapy, to\ncreate synergistic effects and improve overall patient outcomes.<\/p>\n\n\n\n

Target Identification: Identifying appropriate\ntarget genes for siRNA therapy is crucial. Hypotheses could center on advanced\nbioinformatics and screening techniques to identify and validate potential gene\ntargets associated with specific diseases.<\/p>\n\n\n\n

Conclusion<\/strong><\/p>\n\n\n\n

In conclusion, siRNA (small interfering RNA)\ndrug delivery systems have emerged as a promising approach in cancer therapy.\nsiRNAs offer a unique mechanism to silence specific genes involved in cancer\nprogression, making them attractive targets for therapeutic intervention.\nHowever, the successful application of siRNA-based treatments relies on\nefficient and targeted delivery to cancer cells.<\/p>\n\n\n\n

Various delivery systems have been developed\nto overcome the challenges associated with siRNA delivery, including\nnanoparticle-based carriers, lipid-based formulations, viral vectors, and\nconjugates. These systems aim to enhance stability, improve cellular uptake,\nand ensure specific delivery to cancer cells while minimizing off-target\neffects.<\/p>\n\n\n\n

The development of siRNA drug delivery systems\nhas shown promising results in preclinical studies, demonstrating effective\ngene silencing and tumour regression. Targeting specific oncogenes or pathways\nusing siRNAs has shown potential for personalized medicine, allowing for\ntailored treatments based on the genetic profile of individual patients.<\/p>\n\n\n\n

Despite these advancements, several hurdles\nremain to be addressed. Efficient systemic delivery, stability during\ncirculation, avoidance of immune responses, and targeted delivery to tumors are\nongoing challenges in siRNA delivery. Additionally, the optimization of dosing\nregimens and long-term safety evaluations are crucial for the successful\ntranslation of siRNA-based therapies from the laboratory to the clinic.<\/p>\n\n\n\n

In conclusion, siRNA drug delivery systems\nhave demonstrated significant potential in cancer therapy by selectively\ninhibiting the expression of disease-associated genes. Continued research and\ndevelopment efforts are needed to refine delivery strategies, optimize\ntherapeutic efficacy, and address safety concerns. With further advancements,\nsiRNA-based treatments have the potential to revolutionize cancer therapy,\noffering more precise and personalized approaches to combat this devastating\ndisease.<\/p>\n\n\n\n

Acknowledgment<\/strong><\/p>\n\n\n\n

The authors wish to\nexpress their gratitude to Nitte (Deemed to be University) and NGSM Institute\nof Pharmaceutical Sciences for generously providing the essential resources\nrequired for conducting this research.<\/p>\n\n\n\n

Conflict of Interest<\/strong><\/p>\n\n\n\n

There is no conflict of interest.<\/p>\n\n\n\n

Funding Sources<\/strong><\/p>\n\n\n\n

There are no funding sources.<\/p>\n\n\n\n

References<\/strong><\/p>\n\n\n\n

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