Poly Ethylene Glycol Dialdehyde Research Articles

Self‐healing and cell adhesion properties of dynamic and photo‐crosslinking PEG‐based dual networks soft hydrogels

AbstractSelf‐healing involves an autonomic response that repairs damage to living systems. In this study, polyethylene glycol (PEG) underwent aldehyde‐functionalization using the Albrigh Goldman oxidation technique. Flexible, dynamic crosslink points to encourage self‐healing are generated by the formation of acylhydrazone bonds formed between long‐chain PEG dialdehyde and adipic acid dihydrazide. Furthermore, methacrylated PEG was synthesized to support the polymer matrix through dynamic covalent bonds. The hydrogels exhibited self‐healing within the first 4 hours at room temperature and after 24 h. hydrogels with mechanical performance close to the original were obtained. They have good tensile and elongation strength and are well‐suited for interaction with living cells.

Synthesis and characterization of a Schiff base crosslinked hydrogel based on hyperbranched polyglycerol

Formation of a Schiff base crosslinked hydrogel based on hyperbranched aminoterminated polyglycerol and polyethylene glycol dialdehyde and a first insight on its mechanical properties.

Pectin-based self-healing hydrogel through acylhydrazone connection for controlled drug release and enhanced tumor therapy

Biocompatible self-healing hydrogels have important application in drug loading and release for anti-tumor therapy. In this study, biocompatible self-healing hydrogel was designed from pectin acylhydrazide (pec-AH) with polyethylene glycol dialdehyde (PEG DA) cross-linking and the application as DOX delivery carrier for effective tumor treatment was investigated. Results showed that the pec-AH could be easily obtained through hydrazinolysis and the pectin based self-healing hydrogels through PEG DA cross-linking exhibited good mechanical property and flexibility. Importantly, the hydrogels showed excellent biocompatibility and biodegradability both in vitro and in vivo with controlled drug release behavior based on three-dimensional microporous structure. The xenograft CT-26 tumors model experiment in mice revealed the DOX-loaded hydrogel can significantly inhibit tumor growth compared to direct injection of DOX and eliminated the side effect. With above advanced properties, the pectin-based hydrogel holds great potential bio-applications in fields of localized drug delivery for antitumor therapy.

Hyaluronic Acid-Based Microgels and Microgel Networks for Vocal Fold Regeneration

Vocal fold scarring disrupts the viscoelastic properties of the lamina propria that are critical for normal phonation. There is a clinical need for the development of advanced biomaterials that approximate the mechanical properties of the lamina propria for in vivo vocal fold regeneration. We have developed hyaluronic acid (HA)-based microgels and cross-linked microgel networks with tunable degradation and mechanical properties. HA microgels were prepared by cross-linking HA derivatives carrying hydrazide (HAADH) and aldehyde (HAALD) functionalities within the inverse emulsion droplets. Alternatively, poly(ethylene glycol) dialdehyde (PEGDiALD) was employed in place of HAALD. Microgels based on HAADH/HAALD are more resistant to enzymatic degradation than those generated from HAADH/PEGDiALD. In vitro cytotoxicity studies using vocal fold fibroblasts indicate that microgels synthesized from HAADH/HAALD are essentially nontoxic, whereas microgels derived from HAADH/PEGDiALD exhibit certain adverse effects on the cultured cells at high concentration (> or =2 mg/mL). These microgels exhibit residual functional groups that can be used as reactive handles for covalent conjugation of therapeutic molecules. The presence of residual functional groups also allows for subsequent cross-linking of the microgels with other reactive polymers, giving rise to doubly cross-linked networks (DXNs) with tunable viscoelasticity. Mechanical measurements using a torsional wave apparatus indicate that HA-based DXNs exhibit elastic moduli that are similar to those of vocal fold lamina propria at frequencies close to the range of human phonation. These HA-based microgel systems are promising candidates for the treatment of vocal fold scarring, not just as biocompatible filler materials, but as smart entities that can repair focal defects, smooth the vocal fold margin, and potentially soften and dissolve scar tissue.

Synthesis and physicochemical analysis of gelatin-based hydrogels for drug carrier matrices

This study examined the interrelated effect of environmental pH, gelatin backbone modification and crosslinking modality on hydrogel morphology, surface hydrophilicity, in vitro swelling/degradation kinetics, in vitro drug release kinetics and in vivo degradation, inflammatory response and drug release activity. The percent glutaraldehyde fixation had a greater impact on the morphology of the dehydrated hydrogels than gelatin modification. Any decrease in percent glutaraldehyde fixation and/or modification of gelatin with polyethylene glycol dialdehyde (PEG-dial) and/or ethylenediaminetetraacetic dianhydride (EDTAD) increased hydrogel surface hydrophilicity. Swelling/degradation studies showed that modification of gelatin with PEG-dial generally increased the time to reach the maximum swelling weight ratio ( T max) and the time to failure by hydrolysis ( T fail), but had little effect on the maximum swelling weight ratio ( R max) and the weight ratio at failure ( R fail). Modification of gelatin with EDTAD generally had no effect on T max and T fail, but increased R max and R fail. Modification of gelatin with PEG-dial and EDTAD increased R max, but had no effect on T max, R fail, or T fail. Decreasing percent glutaraldehyde fixation generally increased R max and R fail but decreased T max and T fail. Decreasing environmental pH from 7.4 to 4.5 had no effect on any swelling/degradation properties. In vitro drug release studies showed that modification of gelatin with PEG-dial and/or EDTAD generally decreased the maximum mass ratio of drug released ( D max) and the time to reach D max ( T dmax). Percent glutaraldehyde fixation did not significantly affect D max or T dmax (except for EDTAD-modified gelatin hydrogels). In vivo studies showed that gelatin-based hydrogels elicited comparable levels of acute and chronic inflammatory response as that of the empty cage control by 21 d.