Nucleic Acid Delivery Research Articles

Cationized extracellular vesicles for gene delivery

Last decade, extracellular vesicles (EVs) attracted a lot of attention as potent versatile drug delivery vehicles. We reported earlier the development of EV-based delivery systems for therapeutic proteins and small molecule chemotherapeutics. In this work, we first time engineered EVs with multivalent cationic lipids for the delivery of nucleic acids. Stable, small size cationized EVs were loaded with plasmid DNA (pDNA), or mRNA, or siRNA. Nucleic acid loaded EVs were efficiently taken up by target cells as demonstrated by confocal microscopy and delivered their cargo to the nuclei in triple negative breast cancer (TNBC) cells and macrophages. Efficient transfection was achieved by engineered cationized EVs formulations of pDNA- and mRNA in vitro. Furthermore, siRNA loaded into cationized EVs showed significant knockdown of the reporter gene in Luc-expressing cells. Overall, multivalent cationized EVs represent a promising strategy for gene delivery.

Efficient Polymeric Nanoparticle Gene Delivery Enabled Via Tri- and Tetrafunctional Branching.

Poly(β-amino ester) (PBAE) nanoparticles (NPs) show great promise for nonviral gene delivery. Recent studies suggest branched PBAEs (BPBAEs) offer advantages over linear counterparts, but the effect of polymer structure has not been well investigated across many chemical constituents. Here, a library of BPBAEs was synthesized with tri- and tetrafunctional branching. These polymers self-assemble with DNA to form highly cationic, monodisperse NPs with notably small size (∼50 nm). Optimal transfection occurred with polymer structures that featured moderate PBAE branching, enabling complete DNA encapsulation, rapid NP uptake, and robust expression at low DNA doses and polymer amounts. Optimized NPs enabled efficient DNA delivery to diverse cell types in vitro while maintaining high cellular viability, demonstrating significant improvements over a well-performing linear PBAE counterpart. BPBAEs also facilitated efficient mRNA and siRNA delivery, highlighting the versatility of these structures and demonstrating the broad utility of BPBAE NPs as vectors for nucleic acid delivery.

PH-Responsive Micelles Containing Quinine Functionalities Enhance Intracellular Gene Delivery and Expression.

Quinine is a promising building block for creating polymer carriers for intracellular nucleic acid delivery. This is due to its ability to bind to genetic material through intercalation and electrostatic interactions and the balance of hydrophobicity and hydrophilicity dependent on the pH/charge state. Yet, studies utilizing cinchona alkaloid natural products in gene delivery are limited. Herein, we present the incorporation of a quinine functionalized monomer (Q) into block polymer architectures to form self-assembled micelles for highly efficient gene delivery. Q was incorporated into the core and/or the shell of the micelles to introduce the unique advantages of quinine to the system. We found that incorporation of Q into the core of the micelle resulted in acid-induced disassembly of the micelle and a boost in transfection efficiency by promoting endosomal escape. This effect was especially evident in the cancerous cell line, A549, which has a more acidic intracellular environment. Incorporation of Q into the shell of the micelles resulted in intercalative binding to the genetic payload as well as larger micelle-DNA complexes (micelleplexes) from the hydrophobicity of Q in the shell. These factors enable the micelleplexes to be more resistant to serum and have more persistent protein expression post-transfection. Overall, this study is the first to demonstrate the benefits of including quinine functionalities into self-assembled micelles for highly efficient gene delivery and presents a platform for inclusion of other natural products with similar properties into micellar systems.

Enhancing Cytoplasmic Expression of Exogenous mRNA Through Dynamic Mechanical Stimulation.

Ionizable lipid nanoparticles (LNPs) are pivotal in combating COVID-19, and numerous preclinical and clinical studies have highlighted their potential in nucleic acid-based therapies and vaccines. However, the effectiveness of endosomal escape for the nucleic acid cargos encapsulated in LNPs is still low, leading to suboptimal treatment outcomes and side effects. Hence, improving endosomal escape is crucial for enhancing the efficacy of nucleic acid delivery using LNPs. Here, a mechanical oscillation (frequency: 65Hz) is utilized to prompt the LNP-mediated endosomal escape. The results reveal this mechanical oscillation can induce the combination and fusion between LNPs with opposite surface charges, enhance endosomal escape of mRNA, and increase the transfection efficiency of mRNA. Additionally, cell viability remains high at 99.3% after treatment with oscillation, which is comparable to that of untreated cells. Furthermore, there is no obvious damage to mitochondrial membrane potential and Golgi apparatus integrity. Thus, this work presents a user-friendly and safe approach to enhancing endosomal escape of mRNA and boosting gene expression. As a result, this work can be potentially utilized in both research and clinical fields to facilitate LNP-based delivery by enabling more effective release of LNP-encapsulated cargos from endosomes.

Status Quo in the Liposome-Based Therapeutic Strategies Against Glioblastoma: "Targeting the Tumor and Tumor Microenvironment".

Glioblastoma is the most aggressive and fatal brain cancer, characterized by a high growth rate, invasiveness, and treatment resistance. The presence of the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB) poses a challenging task for chemotherapeutics, resulting in low efficacy, bioavailability, and increased dose-associated side effects. Despite the rigorous treatment strategies, including surgical resection, radiotherapy, and adjuvant chemotherapy with temozolomide, overall survival remains poor. The failure of current chemotherapeutics and other treatment regimens in glioblastoma necessitates the development of new drug delivery methodologies to precisely and efficiently target glioblastoma. Nanoparticle-based drug delivery systems offer a better therapeutic option in glioblastoma, considering their small size, ease of diffusion, and ability to cross the BBB. Liposomes are a specific category of nanoparticles made up of fatty acids. Furthermore, liposomes can be surface-modified to target a particular receptor and are nontoxic. This review discusses various methods of liposome modification for active/directed targeting and various liposome-based therapeutic approaches in the delivery of current chemotherapeutic drugs and nucleic acids in targeting the glioblastoma and tumor microenvironment.

Evaluating delivery of peptide nucleic acids to Gram-negative bacteria using differently linked membrane-active peptides and their stapled analogs

Antisense oligonucleotides have been developed as therapeutic compounds, with peptide nucleic acid (PNA) emerging as a promising nucleic acid mimic for antimicrobial applications. To be effective, PNAs must be internalized into bacterial cells, as they are not naturally absorbed. A strategy to improve PNA membrane penetration and cellular uptake involves covalently conjugating them to cell-penetrating peptides. However, these membrane-active peptides can exhibit cytotoxicity, and their efficiency as PNA carriers needs to be enhanced. Therefore, we explored new peptide–PNA conjugates and their linkers to understand how they affect PNA uptake into bacteria. We conjugated PNA to two peptides, anoplin and (KFF)3K, along with their structurally stabilized hydrocarbon-stapled derivatives, and evaluated their transport into various bacterial strains. The PNA sequence targeted bacterial mRNA encoding the essential acyl carrier protein. As linkages, we used either a non-cleavable 8-amino-2,6-dioxaoctanoyl (ethylene glycol, eg1) linker or a reducible disulfide bridge. We found that the hydrocarbon-stapled peptides did not enhance PNA delivery, despite the strong inner- and outer-membrane-penetrating capabilities of the standalone peptides. Additionally, the disulfide bridge linkage, which is cleavable in the bacterial cytoplasm, decreased the antimicrobial activity of the peptide–PNA conjugates. Notably, we identified anoplin as a new potent PNA carrier peptide, with the anoplin–eg1–PNA conjugate demonstrating antibacterial activity against E. coli and S. Typhimurium strains in the 2–4 µM range.

Precise Preparation of Supramolecular Spherical Nucleic Acids for Nucleolin-Targeted Gene Delivery.

Molecular spherical nucleic acids (m-SNAs) are a second generation of spherical nucleic acids (SNAs), which are of significance in potential application of targeted delivery of nucleic acids or gene regulation due to their defined molecular structures. Nevertheless, m-SNAs typically involve a single DNA sequence which greatly limits its functions as either targeting purpose or gene regulation. In response, we proposed here a third generation, supramolecular spherical nucleic acids (Supra-SNAs) with two different sequences to achieve both above-mentioned functions. Specifically, we constructed a series of supramolecular self-assembly structures by coupling a cell membrane receptor (i.e., nucleolin)-recognizing aptamer (AS1411)-modified adamantine as targeting probe and human epithelial growth factor receptor 2 (HER2) antisense-functionalized β-cyclodextrin to specifically inhibit the overexpression of HER2 proteins for gene regulations. In comparison to the m-SNA precursors, such Supra-SNA structures exhibited enhanced levels of resistance to nuclease degradation, cellular uptake, gene regulation capabilities and tumor retention capacity. We demonstrated that Supra-SNAs exhibited optimal cell suppression rates and cell apoptosis via a phosphatidylinositol 3-kinase/protein kinase B signaling pathway. The well-defined molecular structures provide an attractive platform for investigating interrelationship between structure and property at the molecular level.

Precise Preparation of Supramolecular Spherical Nucleic Acids for Nucleolin‐Targeted Gene Delivery

AbstractMolecular spherical nucleic acids (m‐SNAs) are a second generation of spherical nucleic acids (SNAs), which are of significance in potential application of targeted delivery of nucleic acids or gene regulation due to their defined molecular structures. Nevertheless, m‐SNAs typically involve a single DNA sequence which greatly limits its functions as either targeting purpose or gene regulation. In response, we proposed here a third generation, supramolecular spherical nucleic acids (Supra‐SNAs) with two different sequences to achieve both above‐mentioned functions. Specifically, we constructed a series of supramolecular self‐assembly structures by coupling a cell membrane receptor (i.e., nucleolin)‐recognizing aptamer (AS1411)‐modified adamantine as targeting probe and human epithelial growth factor receptor 2 (HER2) antisense‐functionalized β‐cyclodextrin to specifically inhibit the overexpression of HER2 proteins for gene regulations. In comparison to the m‐SNA precursors, such Supra‐SNA structures exhibited enhanced levels of resistance to nuclease degradation, cellular uptake, gene regulation capabilities and tumor retention capacity. We demonstrated that Supra‐SNAs exhibited optimal cell suppression rates and cell apoptosis via a phosphatidylinositol 3‐kinase/protein kinase B signaling pathway. The well‐defined molecular structures provide an attractive platform for investigating interrelationship between structure and property at the molecular level.

A Cell-Free Kinetic Analysis of Ionizable Lipid Hydrolysis.

The prolonged retention of ionizable lipids within the body limits the repeated dosing of lipid nanoparticles (LNPs) for nucleic acid delivery. While most ionizable lipids are primarily metabolized in the liver via the enzymatic hydrolysis of ester bonds, elimination half-lives can range from several hours to days. The development of compounds that undergo rapid biodegradation remains a major engineering challenge in the absence of standardized biodegradability assessments in the early stages of drug discovery. Here, we analyze and compare the hydrolysis kinetics of well-known ionizable lipids (ALC-0315, DLin-MC3-DMA, LP-01, L319, and SM-102) using optimized cell-free reactions monitored by 1H NMR. Unlike conventional analytical techniques, these NMR-based methods are universal and suitable for high-throughput screening. We demonstrate that enzyme-catalyzed and base hydrolysis reactions can predict whether ionizable lipids undergo fast or slow liver elimination, as our results are in alignment with prior pharmacokinetic studies. Furthermore, we show that the hydrolysis kinetics of ionizable lipids vary by several orders of magnitude depending on steric effects. This study provides a framework to expedite the discovery of rapidly degradable ionizable lipids, with implications for improving the therapeutic index of LNP-based drugs.

Spatially-Resolved Organoid Transfection by Porous Silicon-Mediated Optoporation.

Engineering the spatial organisation of organotypic cultures is pivotal for refining tissue models that are useful for gaining deeper insights into complex, non-cell autonomous processes. These advanced models are key to improving the understanding of fundamental biological mechanisms and therapeutic strategies. Controlling gene regulation through spatially-resolved delivery of nucleic acids provides an attractive approach to produce such tissue models. An emerging strategy for spatially-resolved transfection uses photosensitizing nanoparticles coupled with laser pulses to optoporate cells in culture and locally mediate gene delivery. However, localized optoporation in 3D systems remains challenging. Here we propose a solution to this longstanding hurdle, demonstrating that porous silicon nanoparticles are a safe and bioresorbable photosensitising nanomaterial capable of spatially-resolved transfection of mRNA in MCF-7 organoids by near-infrared two-photon optoporation. Functionalization with an azobenzene-lysine photo-switchable moiety enhances the transfection efficiency of the nanoparticles up to 84% in a 2D cell system. Moreover, the nanoparticles enable spatially selective mRNA transfection to MCF-7 spheroids, demonstrating targeted gene delivery in complex 3D cellular environments. The approach for spatially-resolved 3D optoporation offers a way forward for the design of tailored spheroids and organoids by spatially selective nucleic acids delivery.

Toll-like receptor 7 protects against intestinal inflammation and restricts the development of colonic tissue-resident memory CD8+ T cells.

The maintenance of intestinal homeostasis depends on a complex interaction between the immune system, intestinal epithelial barrier, and microbiota. Alteration in one of these components could lead to the development of inflammatory bowel diseases (IBD). Variants within the autophagy gene ATG16L1 have been implicated in susceptibility and severity of Crohn's disease (CD). Individuals carrying the risk ATG16L1 T300A variant have higher caspase 3-dependent degradation of ATG16L1 resulting in impaired autophagy and increased cellular stress. ATG16L1-deficiency induces enhanced IL-1β secretion in dendritic cells in response to bacterial infection. Infection of ATG16L1-deficient mice with a persistent strain of murine norovirus renders these mice highly susceptible to dextran sulfate sodium colitis. Moreover, persistent norovirus infection leads to intestinal virus specific CD8+ T cells responses. Both Toll-like receptor 7 (TLR7), which recognizes single-stranded RNA viruses, and ATG16L1, which facilitates the delivery of viral nucleic acids to the autolysosome endosome, are required for anti-viral immune responses. However, the role of the enteric virome in IBD is still poorly understood. Here, we investigate the role of TLR7 and ATG16L1 in intestinal homeostasis and inflammation. At steady state, Tlr7-/- mice have a significant increase in large intestinal lamina propria (LP) granzyme B+ tissue-resident memory CD8+ T (TRM) cells compared to WT mice, reminiscent of persistent norovirus infection. Deletion of Atg16l1 in myeloid (Atg16l1ΔLyz2 ) or dendritic cells (Atg16l1ΔCd11c ) leads to a similar increase of LP TRM. Furthermore, Tlr7-/- and Atg16l1ΔCd11c mice were more susceptible to dextran sulfate sodium colitis with an increase in disease activity index, histoscore, and increased secretion of IFN-γ and TNF-α. Treatment of Atg16l1ΔCd11c mice with the TLR7 agonist Imiquimod attenuated colonic inflammation in these mice. Our data demonstrate that ATG16L1-deficiency in myeloid and dendritic cells leads to an increase in LP TRM and consequently to increased susceptibility to colitis by impairing the recognition of enteric viruses by TLR7. In conclusion, the convergence of ATG16L1 and TLR7 signaling pathways plays an important role in the immune response to intestinal viruses. Our data suggest that activation of the TLR7 signaling pathway could be an attractive therapeutic target for CD patients with ATG16L1 risk variants.

Spleen Targeting Nucleic Acid Delivery Vector Based on Metal-Organic Frameworks.

Nucleic acids have attracted increasing attention as drugs due to their fascinating advantages, such as long-term efficacy and ease of preparation compared to proteins. The nucleic acid therapy relies heavily on delivery vectors, which can prevent the degradation of nucleic acids while assisting them in cellular internalization. However, commonly used nonviral vector liposomes easily accumulate in the liver, which can limit their application in extrahepatic diseases. Herein, a potential spleen targeting vector for nucleic acids is developed based on the metal-organic frameworks. The plasmids are encapsulated inside the nanoscale zeolitic imidazolate framework (ZIF) via coprecipitation. The co-encapsulation of the cationic polymer poly(ether imide) (PEI) and the stabilizer polyvinylpyrrolidone (PVP) can significantly improve particle dispersion and stability. The prepared nanoparticles allow efficient transfection in vitro, mainly through clathrin-mediated and caveolae-mediated endocytosis. The biodistribution in mice shows that 46% of the nanoparticles accumulate in the spleen, which is much higher than that of the liposomes. The vector can successfully deliver plasmids to extrahepatic organs for protein synthesis and even induce an immune response. The elaborate ZIF-based nanoparticle may offer a new route for extrahepatic, especially spleen targeting delivery for the nucleic acids.

Enhancing Cytoplasmic Expression of Exogenous mRNA through Dynamic Mechanical Stimulation.

Ionizable lipid nanoparticles (LNPs) have been pivotal in combating COVID-19, and numerous preclinical and clinical studies have highlighted their potential in nucleic acid-based therapies and vaccines. However, the effectiveness of endosomal escape for the nucleic acid cargos encapsulated in LNPs is still low, leading to suboptimal treatment outcomes and side effects. Hence, improving endosomal escape is crucial for enhancing the efficacy of nucleic acid delivery using LNPs. Here, a mechanical oscillation (frequency: 65 Hz) is utilized to prompt the LNP-mediated endosomal escape. The results reveal this mechanical oscillation can induce the combination and fusion between LNPs with opposite surface charges, enhance endosomal escape of mRNA, and increase the transfection efficiency of mRNA. Additionally, cell viability remains high at 99.3% after treatment with oscillation, which is comparable to that of untreated cells. Furthermore, there is no obvious damage to mitochondrial membrane potential and Golgi apparatus integrity. Thus, this work presents a user-friendly and safe approach to enhancing endosomal escape of mRNA and boosting gene expression. As a result, our work can be potentially utilized in both research and clinical fields to facilitate LNP-based delivery by enabling more effective release of LNP-encapsulated cargos from endosomes.

Piperazine‐derived bisphosphonate‐based ionizable lipid nanoparticles enhance mRNA delivery to the bone microenvironment

Nucleic acid delivery with mRNA lipid nanoparticles are being developed for targeting a wide array of tissues and cell types. However, targeted delivery to the bone microenvironment remains a significant challenge in the field. We report bone‐targeting ionizable lipids featuring a robust piperazine backbone, which forms strong interactions with hydroxyapatite ([Ca5(PO4)3OH]), a key component of mineralized tissues. These lipids, conjugated with derivatives of bisphosphates, demonstrate biocompatibility and low toxicity in vitro and in vivo. Our findings demonstrate the role of a piperazine backbone of a novel ionizable lipid that presents a bisphosphonate group to facilitate bone delivery. This research illustrates the rational design of ionizable lipids for next‐generation bone‐targeting delivery systems.

Piperazine-derived bisphosphonate-based ionizable lipid nanoparticles enhance mRNA delivery to the bone microenvironment.

Nucleic acid delivery with mRNA lipid nanoparticles are being developed for targeting a wide array of tissues and cell types. However, targeted delivery to the bone microenvironment remains a significant challenge in the field. We report bone-targeting ionizable lipids featuring a robust piperazine backbone, which forms strong interactions with hydroxyapatite ([Ca5(PO4)3OH]), a key component of mineralized tissues. These lipids, conjugated with derivatives of bisphosphates, demonstrate biocompatibility and low toxicity in vitro and in vivo. Our findings demonstrate the role of a piperazine backbone of a novel ionizable lipid that presents a bisphosphonate group to facilitate bone delivery. This research illustrates the rational design of ionizable lipids for next-generation bone-targeting delivery systems.

Stable Polymer-Lipid Hybrid Nanoparticles Based on mcl-Polyhydroxyalkanoate and Cationic Liposomes for mRNA Delivery.

Background/Objectives: The development of polymer-lipid hybrid nanoparticles (PLNs) is a promising area of research, as it can help increase the stability of cationic lipid carriers. Hybrid PLNs are core-shell nanoparticle structures that combine the advantages of both polymer nanoparticles and liposomes, especially in terms of their physical stability and biocompatibility. Natural polymers such as polyhydroxyalkanoate (PHA) can be used as a matrix for the PLNs' preparation. Methods: In this study, we first obtained stable cationic hybrid PLNs using a cationic liposome (CL) composed of a polycationic lipid 2X3 (1,26-bis(cholest-5-en-3β-yloxycarbonylamino)-7,11,16,20-tetraazahexacosane tetrahydrochloride), helper lipid DOPE (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine), and the hydrophobic polymer mcl-PHA, which was produced by the soil bacterium Pseudomonas helmantisensis P1. Results: The new polymer-lipid carriers effectively encapsulated and delivered model mRNA-eGFP (enhanced green fluorescent protein mRNA) to BHK-21 cells. We then evaluated the role of mcl-PHA in increasing the stability of cationic PLNs in ionic solutions using dynamic light scattering data, electrophoretic mobility, and transmission electron microscopy techniques. Conclusions: The results showed that increasing the concentration of PBS (phosphate buffered saline) led to a decrease in the stability of the CLs. At high concentrations of PBS, the CLs aggregate. In contrast, the presence of isotonic PBS did not result in the aggregation of PLNs, and the particles remained stable for 120 h when stored at +4 °C. The obtained results show that PLNs hold promise for further in vivo studies on nucleic acid delivery.

Supplementation with ions enhances the efficiency of nucleic acid delivery with cell-penetrating peptides

The successful delivery of therapeutic nucleic acids (NAs) into eukaryotic cells is essential for numerous biomedical applications, including gene therapy, gene silencing, and genome editing. Cell-penetrating peptides (CPPs) have claimed significant attention as delivery vehicles due to their inherent ability to penetrate cellular membranes and efficiently transport cargo, including NAs, into the cells. However, further optimization and a deeper understanding of underlying mechanisms are necessary for such transfection methods. Previous studies have demonstrated that Ca2+ ions can significantly enhance NA delivery efficiency when included in transfection media or CPP/NA nanoparticles during preparation. Similar effects have been observed for Mg2+, but the impact of other ions in this context has not been thoroughly investigated. In this study, we supplemented the CPP/NA formulations with various inorganic biocompatible ions by introducing solutions of the respective salts to colloidal nanoparticles at the preparation stage. Our results indicated that supplementing the CPP/NA formulations with certain salt solutions enhanced the biological effect achieved with NAs while also influencing nanoparticle size, surface charge, complexation stability, and, to some extent, the internalization route. Our findings offer valuable insights for optimizing the formation of CPP nanoparticles to improve NA delivery efficiency.

Kidney-Targeted Delivery of Nonviral Nucleic Acids Using Noninvasive Transcutaneous Ultrasound Enables Safe, Re-dosable, Titratable, and Durable Gene Expression in Mice and Nonhuman Primates

Kidney-Targeted Delivery of Nonviral Nucleic Acids Using Noninvasive Transcutaneous Ultrasound Enables Safe, Re-dosable, Titratable, and Durable Gene Expression in Mice and Nonhuman Primates

Tetrahedral Framework Nucleic Acids Delivery of Pirfenidone for Anti-Inflammatory and Antioxidative Effects to Treat Idiopathic Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic and irreversible lung disease, and developing an effective treatment remains a challenge. The limited therapeutic options are primarily delivered by the oral route, among which pirfenidone (PFD) improves pulmonary dysfunction and patient quality of life. However, its high dose and severe side effects (dyspepsia and systemic photosensitivity) limit its clinical value. Intratracheal aerosolization is an excellent alternative method for treating lung diseases because it increases the concentration of the drug needed to reach the focal site. Tetrahedral framework nucleic acid (tFNA) is a drug delivery system with exceptional delivery capabilities. Therefore, we synthesized a PFD-tFNA (Pt) complex using tFNA as the delivery vehicle and achieved quantitative nebulized drug delivery to the lungs via micronebulizer for lung fibrosis treatment. In vivo, Pt exhibited excellent immunomodulatory capacity and antioxidant effects. Furthermore, Pt reduced mortality, gradually restored body weight and improved lung tissue structure. Similarly, Pt also exhibited superior fibrosis inhibition in an in vitro fibrosis model, as shown by the suppression of excessive fibroblast activation and epithelial-mesenchymal transition (EMT) in epithelial cells exposed to TGF-β1. Conclusively, Pt, a complex with tFNA as a transport system, could enrich the therapeutic regimen for IPF via intratracheal aerosolization inhalation.

Recent Advances and Future Prospects in Polymer-Mediated Drug Delivery Systems: A Comprehensive Review.

Polymer-based drug carriers have revolutionized the pharmaceutical landscape, providing innovative approaches for efficient drug delivery. These advanced systems have significantly mitigated traditional challenges, offering new avenues for targeted and controlled drug release. This paper aims to explore polymers, focusing on their classification, properties, drug release mechanisms, and pharmaceutical applications while emphasizing recent advancements and future prospects in the field. Polymers can be classified based on their origin, biodegradability, and physical properties. Their unique characteristics, such as biocompatibility, flexibility, and ability to modify surface properties, make them ideal for drug delivery applications. The review delves into various drug release mechanisms employed by polymer-based systems, including diffusion, degradation, swelling, and stimuli-responsive release. These mechanisms ensure a controlled and sustained release of therapeutic agents, enhancing efficacy and reducing side effects. The pharmaceutical applications of polymer-based drug carriers are vast, encompassing targeted delivery to specific tissues or cells, sustained-release formulations, and the delivery of complex molecules like proteins and nucleic acids. Despite their advantages, polymer-based drug delivery systems face limitations, including potential toxicity, stability issues, and manufacturing challenges. Addressing these limitations through continued research and development is crucial for advancing the field. Recent advancements, such as smart polymers and nanotechnology integration, hold promise for overcoming these challenges and improving drug delivery efficiency. In conclusion, polymer-mediated drug delivery systems represent a significant leap forward in pharmaceutical technology. This review highlights the importance of polymers in modern medicine, their potential to revolutionize drug delivery, and the ongoing efforts to optimize their use in clinical applications.