Review of Applications and Future Prospects of Stimuli-Responsive Hydrogel Based on Thermo-Responsive Biopolymers in Drug Delivery Systems

Abstract

Some of thermo-responsive polysaccharides, namely, cellulose, xyloglucan, and chitosan, and protein-like gelatin or elastin-like polypeptides can exhibit temperature dependent sol–gel transitions. Due to their biodegradability, biocompatibility, and non-toxicity, such biomaterials are becoming popular for drug delivery and tissue engineering applications. This paper aims to review the properties of sol–gel transition, mechanical strength, drug release (bioavailability of drugs), and cytotoxicity of stimuli-responsive hydrogel made of thermo-responsive biopolymers in drug delivery systems. One of the major applications of such thermos-responsive biopolymers is on textile-based transdermal therapy where the formulation, mechanical, and drug release properties and the cytotoxicity of thermo-responsive hydrogel in drug delivery systems of traditional Chinese medicine have been fully reviewed. Textile-based transdermal therapy, a non-invasive method to treat skin-related disease, can overcome the poor bioavailability of drugs from conventional non-invasive administration. This study also discusses the future prospects of stimuli-responsive hydrogels made of thermo-responsive biopolymers for non-invasive treatment of skin-related disease via textile-based transdermal therapy.

An Injectable Hybrid Gelatin Methacryloyl (GelMA)/Phenyl Isothiocyanate-Modified Gelatin (Gel-Phe) Bioadhesive for Oral/Dental Hemostasis Applications

“…Gelatin is a natural polymer obtained from denatured collagen. Gelatin's structure, similar to collagen, endows it with biocompatible and biodegradable properties-such as bioadhesives, drug carriers, or substrates in biomedical applications [21][22][23]. Moreover, a gelatin hydrogel offers a hemostatic function because it could swell through the absorption of blood, promote the aggregation of platelets, and then activate the platelets to accelerate the blood clotting [24].…”

Application of Sol–Gels for Treatment of Gynaecological Conditions—Physiological Perspectives and Emerging Concepts in Intravaginal Drug Delivery

“…Gelatin forms a gel when the temperature is lowered, due to the conversion of coils into helices through hydrogen bonding as well as van der Waals forces, and hence is grafted with other polymers to ensure the desired sol–gel transition in the human body [ 204 ]. For instance, gelatin combined with poly- N -isopropylacrylamide produces a thermoresponsive matrix, which undergoes rapid gelation at 37 °C [ 8 ].…”

A Critical Review on Polymeric Biomaterials for Biomedical Applications

“…Hydrogels are widely used in the biomedical and tissue engineering applications due to their efficient loading and release of active molecules and drugs. In recent years, stimuli responsive hydrogels have received increasing attention due to their controllable release of drug using external stimuli, such as temperature, pH, light, and ultrasound [ 83 ]. These stimuli responsive hydrogels are termed as smart polymeric drug delivery systems that are capable of controlled drug release and can protect the loaded drug from easy degradation.…”

“…The polymers with lower critical solution temperature (LCST) will be the best choice for the preparation of thermal responsive hydrogels, since they form hydrogels only above its LCST. The sol-gel transition of these thermally responsive polymers at LCST closely resembles the folding of a protein under particular temperature [ 83 , 84 , 85 ].…”