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Natural Polymers and Fibers in Drug Delivery

Dr. Meghraj V. Suryawanshi, Department of Pharmaceutics, Sandip Institute of Pharmaceutical Sciences (SIPS), Affiliated To Savitribai Phule Pune University (SPPU)

Akshata Yashwant Patne, Graduate Programs, Taneja College of Pharmacy; Center for Research and Education in Nanobioengineering, Department of Internal Medicine, Morsani College of Medicine, University of South Florida

Natural polymers and fibers are pivotal in drug delivery, offering biocompatibility, biodegradability, and controlled release via nanoparticles, hydrogels, and scaffolds to enable advanced personalized therapies. Natural polymers offer biocompatibility, biodegradability, and sustainability for drug delivery. Innovations such as chemical modifications, nanotechnology, microfluidics, and 3D printing enhance their mechanical strength, drug release properties, and targeting ability. These advances support precise, controlled delivery and customisation, making natural polymers increasingly valuable in pharmaceutical and biomedical applications.

Introduction

Advancements in drug delivery have become increasingly critical due to the growing demand for more effective, targeted, and personalized therapies. Modern drug delivery systems are designed not only to enhance the bioavailability and release of drugs but also to optimise pharmacokinetic parameters such as absorption, distribution, metabolism, and excretion (ADME), with the goal of improving therapeutic efficacy. In addition, they play a key role in minimising toxicity and enabling controlled or sustained drug release. Traditional delivery methods often lack the precision required for individualised treatment, prompting the development of advanced delivery approaches. These newer systems employ internal or external stimuli to trigger drug release and allow site-specific action, resulting in improved therapeutic outcomes [1].

Among the various components of drug delivery systems, carriers are essential, particularly polymer-based carriers. These are broadly classified into natural and synthetic polymers. Natural polymers have gained prominence due to their renewable origin, superior biocompatibility, biodegradability, and ease of chemical modification. Their inherent flexibility and adaptability make them ideal for designing delivery platforms tailored to specific therapeutic needs. Structurally, natural polymers can effectively interact with biological environments, facilitating targeted and localised drug delivery. Moreover, they can be blended with other natural or synthetic materials to create hybrid systems that further enhance performance.

Natural polymers, particularly polysaccharides and proteins, offer significant advantages in biomedical applications such as cancer therapy, wound healing, and tissue engineering. Their structural similarity to biological molecules allows seamless integration with physiological systems, enabling controlled, targeted, and stimuli-responsive drug release [2]. As the demand for safer, more efficient, and sustainable delivery systems grows, natural polymers are increasingly favored over synthetic counterparts, which often suffer from limitations such as toxicity, high production costs, and environmental concerns. The pharmaceutical industry continues to explore these naturally derived materials not only for their functional capabilities as drug carriers but also for their environmentally friendly profile, making them a promising alternative in the development of next-generation drug delivery systems [3].

Characteristics and Properties of Natural Polymers and Fibers

Table 1 elaborate different characteristics and properties associated with polymers and fibers [4-9]. 

Table 1:  Natural Polymer and Fibers Used For Drug Delivery

 Property  Polysaccharides (e.g., Chitosan, Hyaluronic Acid, Alginate)  Proteins (e.g., Collagen, Silk Fibroin, Gelatin)  Natural Fibers (e.g., Cellulose, Chitin)  

Peptides and Polyesters
 Source  Plant, animal, microbial  Animal, plant  Plant, insect, marine  Synthetically derived, but biologically inspired
 Biodegradability  Highly biodegradable  Biodegradable  Biodegradable  Biodegradable
 Biocompatibility  Excellent  Excellent,  good  Good
 Mechanical Properties  strong but flexible  Flexible  Strong, stiffness and flexibility  Varies
 Encapsulation Efficiency  High, especially for hydrophilic drugs  Moderate to high  Moderate  High, especially for hydrophilic peptides and small molecules
 Stimuli-Responsive Behaviour  respond to pH, temperature, or enzymes  pH, temperature, or external cues  not stimuli-responsive unless modified  Can be designed for stimuli-responsiveness
 Targeting Potential  functionalised for specific cell or tissue targeting  Specific affinity to cellular receptors  Limited targeting  Can be tailored for targeted delivery
 Release Mechanism  Controlled release via degradation, diffusion, or stimuli-triggered  Controlled release via degradation or structural changes  Controlled release via mechanical disruption or degradation  Controlled release based on peptide interactions and degradation
 Applications in DDS  Tissue engineering, wound healing, anticancer therapies, gene delivery  Tissue engineering, wound healing, anticancer therapies, gene delivery  Drug delivery, tissue engineering, wound healing (e.g., fibers for scaffolds) Drug delivery, targeted therapy, biosensors 
 Advantages  biocompatibility, controlled degradation  Biologically active, easy to modify, excellent mechanical strength  Biodegradable, renewable, low cost, strong mechanical properties Customisable, biodegradable, high specificity
 Disadvantages  Limited mechanical strength for some applications  Can be expensive, sourcing from animals may raise ethical concerns  Requires chemical modification for enhanced properties  Limited availability, may require complex synthesis


Formulation Approaches for Personalized Drug Delivery Systems 

Table 2 illustrated information about use of polymers and fibers as polymeric scaffold [10-14].

Table 2: Polymeric Scaffold

 Property  Gelatin  Chitosan (CS)  Alginate  Silk Proteins  Hyaluronic Acid (HAc)
 Source  Derived from irreversible hydrolysis of collagen  Natural polysaccharide derived from chitin  Derived from brown seaweeds  Secreted by arthropods mainly fibroin and sericin  A glycosaminoglycan (GAG) found in connective tissue, synthesized by hyaluronan synthases
 Structure  Composed of smaller peptides, mainly glycine, proline, and hydroxyproline  Copolymer of N-acetyl D-glucosamine and D-glucosamine  Linear unbranched polysaccharide  Fibrous protein composed of a structural core and a hydrophilic protein coating  Repeating disaccharide units of N-acetyl-D-glucosamine and D-glucuronic acid
 Key Characteristics  Biodegradable, soluble, biocompatible, lower natigenicity than collagen  Biodegradable, biocompatible, adhesive, antibacterial properties  Forms soft hydrogels with Ca²⁺, biocompatible, used for sustained release  Unique mechanical properties, environmental stability,morphologic flexibility, tunable biodegradability  Biocompatible, hydrophilic, non-immunogenic, easy to modify chemically, supports osteoprogenitors
  Applications  Biomedicine, drug delivery, tissue engineering, bone tissue engineering  Wound healing, bone tissue engineering, scaffold fabrication  Bone tissue engineering , scaffolds for drug delivery, wound healing, large bone defect regeneration  Bone tissue engineering , scaffold for osteogenesis, tissue regeneration  Bone tissue engineering, drug delivery, hydrogels for controlled release
 Manufacturing Methods   Electrospinning, co-solvent approach for nanofibers, with HA or PCL for scaffolds  Electrospinning, lyophilization, forming porous scaffolds with interconnected pores  Freeze-drying, co-precipitation with HA, internal gelation, electrospinning, lyophilization, composite formation  Electrospinning, 3D printing, fiber deposition, particulate leaching, solvent- or water-based procedures Can be modified with PEG, AEMA for controlled release, UV crosslinking, and sol-gel transition
 Scaffold Types  Nanofibers, composites with chitosan, PCL, HA, gold nanoparticles used in orthopedic applications  Highly porous scaffolds, nanofibers, films, sponges, beads, often  multilayers, composites  Films, hydrogels, fibers, 3D porous structures, electrospun mats Hydrogels, crosslinked films, modified scaffolds for enhanced drug delivery and osteogenesis
  Key Benefits  Promotes cell adhesion, proliferation, and differentiation due to RGD sequences; biocompatible  Biocompatible, promotes osteogenesis when combined with growth factors, peptides, or HA

Supports bone regeneration, cell

  Supports osteogenesis, improves bone formation, versatile in scaffold shaping  Enhances osteogenesis, supports cell growth, offers biphasic release for sustained bone formation
 Limitations   Insufficient thermostability without chemical modification  Lack of mechanical strength and cell signaling molecules, fast degradation rate  Requires crosslinking or composite formation for improved mechanical properties and stability  Mechanical strength may require modification or combination with other materials  Degradation rate can be too fast without modification, chemical modifications may be needed


Stability Considerations and Compatibility Studies of Natural Polymers and Fibers

Natural polymers and fibers are widely used in drug delivery due to their biocompatibility, biodegradability, and sustainability [15, 16]. However, several stability and compatibility challenges need consideration:

  • Microbial Contamination: Natural materials are prone to microbial load due to environmental exposure. Solution: Use sterilization methods (UV/gamma radiation) and maintain hygienic production environments.
  • Batch-to-Batch Variation: Environmental factors affect polymer composition, causing inconsistency. Solution: Standardize sourcing and processing with consistent quality control.
  • Uncontrolled Hydration Rate: Hydration rates vary due to plant composition. Solution: Optimise formulations, apply hydrophobic treatments, and adjust processing.
  • Slow Production: Plant growth limitations affect production speed. Solution: Use faster-growing varieties or engineered polymers to enhance yield.
  • Heavy Metal Contamination: Plants may absorb metals from soil. Solution: Use clean cultivation methods and bioremediation practices.
  • Fiber-Matrix Interface Issues: Poor bonding leads to weak composites. Solution: Apply chemical treatments (e.g., alkali) to enhance adhesion.
  • Water Absorption: Leads to swelling and degradation. Solution: Use hydrophobic materials and fiber surface treatments to minimise absorption.
  • Moisture Durability: Affects dimensional and mechanical stability. Solution: Apply water-repellent coatings and moisture-resistant matrices.
  • UV Radiation & Weathering: Causes degradation and strength loss. Solution: Add UV stabilizers and protective coatings.
  • Thermal Degradation: Reduces mechanical strength. Solution: Use thermally stable fibers and matrices with added stabilizers.
  • Moisture-Thermal Interaction: Combined effects lead to damage. Solution: Control processing conditions and use hybrid composites for better resistance.

Regulatory Perspectives and Innovations in Natural Polymers for Drug Delivery

Natural polymers, widely used as excipients in drug delivery, are regulated by agencies like the USFDA and EMA to ensure safety, quality, and performance. In the U.S., these are governed under the Food, Drug, and Cosmetic Act, with quality standards defined by USP and Ph. Eur. Monographs. In Europe, approved additives are assigned E-numbers, while the International Numbering System (INS) applies globally [17, 18].

Regulatory authorities require that both in vitro and in vivo studies demonstrate consistent drug delivery performance and therapeutic efficacy. A major challenge in natural polymer-based formulations is stability, affected by pH, temperature, and humidity. Regulatory oversight focuses on ensuring long-term stability and minimising degradation under variable conditions [19, 20].

Emerging trends emphasize sustainable and efficient delivery systems, driving innovations in polymer modification and engineering. Chemical modifications enhance mechanical strength and drug release behavior for controlled and targeted delivery. Integrating natural polymers with nanotechnology allows site-specific drug delivery, while combinations with 3D printing and microfluidics offer customized, patient-specific treatments. These technologies enable precise fabrication of delivery devices, significantly improving therapeutic outcomes.

Reference

  1. Tong X, Pan W, Su T, Zhang M, Dong W, Qi X, “Recent advances in natural polymer-based drug delivery systems.” React. Funct. Polym. 2020, 148(January), 104501. 
  2. Kulbacka J, Choromańska A, Łapińska Z, Saczko J, “Natural polymers in photodynamic therapy and diagnosis.” Polim. Med. 2021, 51(1), 33–41. 
  3. Hu Q, Lu Y, Luo Y, “Recent advances in dextran-based drug delivery systems: From fabrication strategies to applications.” Carbohydr. Polym. 2021, 264, 117999. 
  4. Yuan N, Shao K, Huang S, Chen C, “Chitosan, alginate, hyaluronic acid and other novel multifunctional hydrogel dressings for wound healing: A review.” Int. J. Biol. Macromol. 2023, 240, 124321. 
  5. Zheng H, Zuo B, “Functional silk fibroin hydrogels: preparation, properties and applications.” J. Mater. Chem. B. 2021, 9(5), 1238–58. 
  6. Naomi R, Bahari H, Ridzuan PM, Othman F, “Natural-Based Biomaterial for Skin Wound Healing (Gelatin vs. Collagen): Expert Review.” Polym. 2021, Vol. 13, Page 2319. 2021, 13(14), 2319. 
  7. Yu Z, Ji Y, Bourg V, Bilgen M, Meredith JC, “Chitin- and cellulose-based sustainable barrier materials: a review.” Emergent Mater. 2020, 3(6), 919–36. 
  8. Zhu YS, Tang K, Lv J, “Peptide-drug conjugate-based novel molecular drug delivery system in cancer.” Trends Pharmacol. Sci. 2021, 42(10), 857–69. 
  9. Pothupitiya JU, Zheng C, Saltzman WM, “Synthetic biodegradable polyesters for implantable controlled-release devices.” Expert Opin. Drug Deliv. 2022, 19(10), 1351–64.
  10. Purohit SD, Bhaskar R, Singh H, Yadav I, Gupta MK, Mishra NC, “Development of a nanocomposite scaffold of gelatin-alginate-graphene oxide for bone tissue engineering.” Int. J. Biol. Macromol. 2019, 133, 592–602. 
  11. Khor E, Lim LY, “Implantable applications of chitin and chitosan.” Biomaterials. 2003, 24(13), 2339–49. 
  12. Filippi M, Born G, Chaaban M, Scherberich A, “Natural Polymeric Scaffolds in Bone Regeneration.” Front. Bioeng. Biotechnol. 2020, 8(May) 
  13. Bhattacharjee P, Kundu B, Naskar D, Kim HW, Maiti TK, Bhattacharya D, et al., “Silk scaffolds in bone tissue engineering: An overview.” Acta Biomater. 2017, 63, 1–17. 
  14. Zhao N, Wang X, Qin L, Zhai M, Yuan J, Chen J, et al., “Effect of hyaluronic acid in bone formation and its applications in dentistry.” J. Biomed. Mater. Res. A. 2016, 104(6), 1560–9.
  15. Rajeswari S, “Natural Polymers: a Recent Review.” World J. Pharm. Pharm. Sci. 2017,(June), 472–94. 
  16. Mohammed M, Rahman R, Mohammed AM, Adam T, Betar BO, Osman AF, et al., “Surface treatment to improve water repellence and compatibility of natural fiber with polymer matrix: Recent advancement.” Polym. Test. 2022, 115(May), 107707.
  17. Salave S, Rana D, Sharma A, Bharathi K, Gupta R, Khode S, et al., “Polysaccharide Based Implantable Drug Delivery: Development Strategies, Regulatory Requirements, and Future Perspectives.” Polysaccharides. 2022, 3(3), 625–54. 
  18. Jain S, Jain A, Jain R, Chauhan NS, “Potential of natural polymeric materials in pharmaceutics.” Pharmacol. Res. - Nat. Prod. 2024, 2(October 2023), 100014.
  19. Gupta MK, Suryawanshi M, Shrivastava B. A bird eye view on natural gums and mucilage used in drug delivery system. International Journal of Pharmaceutical Sciences and Nanotechnology (IJPSN). 2023 Feb 14;16(1):6381-9.
  20. Mahajan H, Suryawanshi M, Sarode R, Gujarathi P. Polysaccharides from Nature to Technology: Grafting Techniques and their Applications. Current Applied Polymer Science. 2025 Mar 17.
Dr. Meghraj V. Suryawanshi

Dr. Meghraj V. Suryawanshi is an Associate Professor and Co-Founder of Sandip Institute of Pharmaceutical Sciences. He holds M.Pharm, MBA, PDCR, and Ph.D. degrees. With over 7 years of research experience and 4 years in teaching, his expertise lies in polymer science, novel drug delivery systems (NDDS), and intellectual property rights (IPR). Dr. Suryawanshi has authored more than 55 publications, 8 books, and holds several patents. He actively leads innovative pharmaceutical research with a strong focus on translational impact.

Akshata Yashwant Patne

Akshata Yashwant Patne is a pharmaceutical nanotechnology expert with over 3 years of experience in clinical research, drug delivery, and AI-driven therapeutics. She has led nanoparticle-based studies, published peer-reviewed articles, and actively mentors students, combining science, innovation, and leadership across academia, research, and global scientific communities.