Localized, on-demand, sustained drug delivery from biopolymer-based materials

ABSTRACT

Introduction

Local drug delivery facilitiates higher concentrations of drug molecules at or near the treatment site to enhance treatment efficiency and reduce drug toxicity and other systemic side effects. However, local drug delivery systems face challenges in terms of encapsulation, delivery, and controlled release of therapeutics.

Areas covered

We provide an overview of naturally derived biopolymer-based drug delivery systems for localized, sustained, and on-demand treatment. We introduce the advantages and limitations of these systems for drug encapsulation, delivery, and local release, as well as recent applications.

Expert opinion

Naturally derived biopolymers like cellulose, silk fibroin, chitosan, alginate, hyaluronic acid, and gelatin are good candidates for localized drug delivery because they are readily chemically modified, biocompatible, biodegradable (with the generation of metabolically compatible degradation products), and can be processed in aqueous and ambient environments to maintain the bioactivity of various therapeutics. The tradeoff between the effective treatment dosage and the response by local healthy tissue should be balanced during the design of these delivery systems. Future directions will be focused on strategies to design tunable and controlled biodegradation rates, as well as to explore commercial utility in substituting biopolymer-based systems for currently utilized synthetic polymers for implants for drug delivery.

KEYWORDS:

• Biopolymer
• biodegradation
• hydrogel
• localized drug delivery
• medical implant
• on-demand release
• sustained release

Article highlights

• Advantages of natural biopolymer-based drug systems for local delivery and processing strategies utilized to load and deliver drugs

• Drug release mechanisms include passive and active options; diffusion, wireless activation, and other modes to control release and staged release

• Implant design with degradation

• Healthy tissue responses to drug-loaded natural biopolymer-based implants

Acknowledgments

The authors thank Yu-Ting L. Dingle for her assistance with the illustrations.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

We thank the NIH (P41EB027062, R01NS094218) for support of some of the studies reported in this review article.