Synthesis and Characterization of Biodegradable Polymers from Lactic Acid-Derived Monomers for Controlled Drug Release Systems

Project Abstract

Synthesis and characterization of biodegradable polymers from lactic acid-derived monomers for controlled drug release systems were explored to address the growing demand for safe, sustainable, and patient-tailored therapeutics. This study presents a comprehensive approach combining green chemistry principles, ring-opening polymerization, and advanced material characterization to engineer polymers with tunable degradation rates, mechanical integrity, and drug-release profiles suitable for sensitive biomedical applications. Lactic acid-derived monomers were polymerized using bulk and solution polymerization techniques, employing catalyst systems optimized to minimize residual metal content and achieve high molar masses with narrow polydispersity. The resulting poly(lactic acid) (PLA) and its copolymers with complementary biodegradable monomers were systematically varied to modulate crystallinity, hydrophilicity, and thermal properties, thereby influencing hydrolytic degradation and drug diffusion pathways. A suite of in vitro and in vivo-compatible model drugs, including hydrophobic and hydrophilic compounds, were incorporated using solvent casting, melt extrusion, and electrospinning to generate diverse dosage forms such as microspheres, films, and nanofibrous matrices. Drug release kinetics were analyzed under simulated physiological conditions to elucid the relationships between polymer composition, matrix morphology, and release mechanisms (diffusion, erosion, and combined processes). Advanced characterization techniques, including differential scanning calorimetry, gel permeation chromatography, X-ray diffraction, scanning electron microscopy, atomic force microscopy, and nuclear magnetic resonance spectroscopy, were employed to correlate molecular architecture with macroscopic performance. The study also investigated surface modification strategies and crosslinking approaches to further tailor degradation rates and enable site-specific delivery. Biocompatibility and cytotoxicity assessments were conducted using standard cell viability assays and hemocompatibility tests to ensure suitability for biomedical implants and injectable systems. Results demonstrated that copolymer composition and tacticity significantly influence crystallinity and hydrolytic degradation, enabling precise control over drug release windows ranging from days to months. PLA-based networks with tuned hydrophilicity achieved sustained release profiles with reduced initial burst, while incorporating co-monomers such as poly(lactic-co-glycolic acid) and poly(lactic-co-caprolactone) enabled more rapid or prolonged release as required. The integration of controlled degradation kinetics with responsive components allowed the development of stimuli-responsive release systems capable of adjusting release rates in response to pH and enzymatic activity. Thermal and rheological analyses revealed processable materials compatible with scalable manufacturing workflows, including melt processing and electrospinning for fabricating patient-friendly dosage forms. This work provides a framework for designing biodegradable polymer matrices from lactic acid-derived monomers that meet the stringent demands of controlled drug delivery, including tailored release profiles, mechanical compatibility with target tissues, and regulatory-friendly biocompatibility. The findings offer practical insights into monomer selection, polymer architecture, and processing conditions that collectively enable translational progress from laboratory-scale synthesis to clinical applications, advancing the development of safer, more effective, and environmentally sustainable drug delivery systems.

Project Overview

What This Project Is About

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This project explores making biodegradable polymers from lactic acid-derived building blocks and studying how they release drugs in a controlled way. It focuses on turning simple, safe ingredients into materials that break down in the body and can slowly deliver a medicine at a chosen rate.

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The Problem It Addresses

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Many medical implants and pills use materials that don’t degrade well in the body, requiring removal surgeries or causing lasting waste. Biodegradable polymers offer safer, patient-friendly options, but they must be tuned to release drugs at the right speed and be compatible with the body. This project aims to bridge that gap by creating and evaluating such polymers.

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Objectives of the Project

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1. Prepare polymers from lactic acid derivatives suitable for drug delivery.
2. Characterize their chemical structure and physical properties.
3. Test how drugs release from the polymers under different conditions.
4. Assess biocompatibility and degradation behavior in simulated environments.
5. Identify processing methods that produce consistent material quality.

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What You Will Do Step by Step

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1. Literature review to understand current materials and drug-release concepts.
2. Synthesize lactic acid-derived monomers and polymerize into test samples.
3. Characterize structure using simple spectroscopy and thermal methods.
4. Embed or load a model drug into the polymer samples.
5. Perform in vitro drug-release assays and measure release profiles.
6. Study how polymer composition affects degradation rate.
7. Evaluate basic biocompatibility with simple cell-friendly tests.
8. Analyze data to relate material properties to release behavior.

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Expected Outcome

Clear understanding of how lactic acid-derived polymers can control drug release, with data showing release rates, degradation behavior, and basic safety indicators. The project should yield candidate formulations for further study and a practical, easy-to-follow guide for preparing similar materials.