The novel polymer-based drug delivery system proposed here is a combination of a biodegradable polymer matrix, a targeting ligand, and a chemotherapeutic drug. The polymer matrix will be composed of poly lactic-co-glycolic acid PLGA , a biodegradable and biocompatible polymer that has been widely used in drug delivery systems. The targeting ligand will be a cancer-specific monoclonal antibody mAb that can selectively bind to cancer cells, ensuring minimal adverse effects on healthy cells. The chemotherapeutic drug will be encapsulated within the PLGA matrix, allowing for controlled and sustained drug release.System Design:1. Polymer matrix: PLGA is chosen as the polymer matrix due to its biodegradability, biocompatibility, and tunable physicochemical properties. The ratio of lactic acid to glycolic acid in the PLGA copolymer can be adjusted to control the degradation rate and drug release profile. Additionally, the molecular weight of PLGA can be tailored to achieve the desired mechanical properties and drug loading capacity.2. Targeting ligand: A cancer-specific mAb will be conjugated to the surface of the PLGA matrix. This mAb will selectively bind to a specific antigen overexpressed on the surface of cancer cells, ensuring targeted drug delivery and minimizing the exposure of healthy cells to the chemotherapeutic drug.3. Chemotherapeutic drug: The drug will be encapsulated within the PLGA matrix during the fabrication process. The drug's physicochemical properties, such as solubility and stability, should be considered to ensure optimal encapsulation efficiency and drug release profile.Mechanism of Drug Release:The drug release from the PLGA matrix occurs through a combination of diffusion and polymer degradation. Initially, the drug diffuses out of the polymer matrix due to the concentration gradient between the drug-loaded matrix and the surrounding environment. As the PLGA matrix degrades via hydrolysis, the drug is further released from the matrix. The degradation rate of PLGA and the drug release profile can be controlled by adjusting the copolymer composition and molecular weight.Potential Benefits of the Proposed System:1. Targeted drug delivery: The cancer-specific mAb ensures that the drug is selectively delivered to cancer cells, minimizing the exposure of healthy cells to the chemotherapeutic drug and reducing adverse side effects.2. Controlled and sustained drug release: The PLGA matrix allows for controlled and sustained drug release, maintaining an effective drug concentration at the tumor site for an extended period and potentially reducing the frequency of drug administration.3. Biodegradability and biocompatibility: The PLGA matrix is biodegradable and biocompatible, ensuring minimal toxicity and inflammation in the body.4. Tunable physicochemical properties: The properties of the PLGA matrix can be tailored to achieve the desired drug release profile, mechanical properties, and drug loading capacity, allowing for customization based on the specific drug and cancer type.In conclusion, the proposed polymer-based drug delivery system combines a biodegradable PLGA matrix, a cancer-specific mAb, and a chemotherapeutic drug to achieve targeted, controlled, and sustained drug release with minimal adverse effects on healthy cells. This system has the potential to improve the efficacy and safety of cancer therapy, ultimately benefiting patients and healthcare providers.