Poly(methyl vinyl ether-co-maleic acid) Hydrogels Containing Cyclodextrins and Tween 85 for Potential Application as Hydrophobic Drug Delivery Systems

Abstract

Hydrogels have been extensively investigated as a platform for drug delivery. However, their use for the delivery of hydrophobic drugs has been limited by their incompatibility with hydrophobic drug molecules. The chemical modification of the structure of the hydrogels to include hydrophobic moieties has been proven to be a good alternative to increase the stability and solubility of hydrophobic drugs in the polymer matrix of the hydrogel. The inclusion of hydroxypropyl-β-cyclodextrins (HPBCD) and Tween ® 85 (T85) within hydrogel matrices has the potential to improve hydrophobic drug loading and release. HPBCD have the ability to host hydrophobic drug molecules in their cone-like structure, forming inclusion complexes through host-guest interactions. On the other hand, T85 is an amphiphilic molecule and, consequently, has the potential to increase hydrophilic drug loading within the hydrogels. In the present work, a new type of hydrogel made from poly(methyl vinyl ether-co-maleic acid) (GAN) and poly(ethylene glycol) (PEG) containing T85 and HPBCD was synthesized for hydrophobic drug release. Hydrogels were based on GAN crosslinked (PEG) and HPBCD and/or T85 via an esterification reaction in the solid state (solvent free). The synthesised hydrogels were characterised using Fourier transform infrared (FTIR) spectroscopy, swelling studies and contact angle measurements. The hydrogels showed swellings ranging from 140 to 180%. The inclusion of T85 in the hydrogels improved the wettability of the materials. On the other hand, the inclusion of HPBCD within the hydrogels decreased the wettability as the contact angle between the hydrogels and water increased with the HPBCD content. Finally, the materials were loaded with an ophthalmic drug, dexamethasone (DX). HPBC-containing hydrogels showed a higher DX uptake and, consequently, they showed a higher capacity of DX release. On the other hand, T85 containing hydrogels did not show any improvement over the hydrogels containing only GAN and PEG. The hydrogels were able to provide sustained DX release over periods of 6 hours.

Exploring the biosynthetic pathway of lignin in Acorus tatarinowii Schott using de novo leaf and rhizome transcriptome analysis

“…In addition, lignin can increase the stability of the antimicrobial properties of wound dressings (35,36). Lignin-based hydrogels, which combine lignin with other polymers, have been used for gene delivery(37), drug delivery (38), and tissue engineering (39,40). This is the first transcriptome sequencing study of two tissues of A. tatarinowii using RNA-Seq technology.…”

“…In addition, lignin can increase the stability of the antimicrobial properties of wound dressings [ 35 , 36 ]. Lignin-based hydrogels, which combine lignin with other polymers, have been used for gene delivery [ 37 ], drug delivery [ 38 ], and tissue engineering [ 39 , 40 ].…”

100th Anniversary of Macromolecular Science Viewpoint: Poly(N-isopropylacrylamide)-Based Thermally Responsive Micelles

“…More importantly, the LCST of PNIPAAm occurs at near physiological conditions (∼32 °C), as first reported by Heskins and Guillet in 1968, rending this stimuli-responsive polymer suitable for biotechnological applications, including molecular imaging, drug delivery, cell separating, tissue engineering, and biosensing. − Another important and valuable feature of PNIPAAm is the feasibility of tuning its LCST by the addition of surfactants, salts, or by the copolymerization with hydrophilic/hydrophobic comonomers. − For example, incorporating a hydrophilic segment (e.g., poly­(acrylamide) or poly­(acrylic acid)) in PNIPAAm can increase the LCST. , However, when hydrophobic monomers (e.g., N - tert -butyl acrylamide) are copolymerized with PNIPAAm, the LCST will be decreased. − Compared with other popular LCST polymers, such as poly­( N , N -diethylacrylamide), , poly­(methyl vinyl ether), , and poly­( N -vinylcaprolactam), , the LCST of PNIPAAm can be more easily fine-tuned and precisely controlled upon copolymerization with other monomers for biomedical use since it is already close to body temperature. Another significant merit of PNIPAAm is the strong hysteresis owing to the coexistence of H-bond donors and acceptors, rendering it a particularly interesting material among thermal transition polymers for specific applications, such as the selective precipitation of enzymes.…”

Fruit pomace-lignin as a sustainable biopolymer for biomedical applications

“…Hydrogels are cross-linked polymers that mimic human tissues in their ability to absorb and retain large masses of biological fluids within their structure (Larrañeta et al, 2019). Due to the presence of a polymeric network, hydrogels can absorb fluids such as water to achieve a mass of approximately one thousand times their dry mass without dissolving (Thakur & Thakur, 2015).…”