Thermoreversible gel for delivery of activin receptor-like kinase 5 inhibitor SB-505124 for glaucoma filtration surgery

Development of a Topical Insulin Polymeric Nanoformulation for Skin Burn Regeneration: An Experimental Approach

Insulin is a peptide hormone with many physiological functions, besides its use in diabetes treatment. An important role of insulin is related to the wound healing process-however, insulin itself is too sensitive to the external environment requiring the protective of a nanocarrier. Polymer-based nanoparticles can protect, deliver, and retain the protein in the target area. This study aims to produce and characterize a topical treatment for wound healing consisting of insulin-loaded poly-DL-lactide/glycolide (PLGA) nanoparticles. Insulin-loaded nanoparticles present a mean size of approximately 500 nm and neutral surface charge. Spherical shaped nanoparticles are observed by scanning electron microscopy and confirmed by atomic force microscopy. SDS-PAGE and circular dichroism analysis demonstrated that insulin preserved its integrity and secondary structure after the encapsulation process. In vitro release studies suggested a controlled release profile. Safety of the formulation was confirmed using cell lines, and cell viability was concentration and time-dependent. Preliminary safety in vivo assays also revealed promising results.

Advancing the stimuli response of polymer-based drug delivery systems for ocular disease treatment

Recent exploitations of stimuli-responsive polymers as ophthalmic drug delivery systems for the treatment of eye diseases are summarized and discussed.

Pluronic-based dual-stimuli sensitive polymers capable of thermal gelation and pH-dependent degradation for in situ biomedical application

Thermo-sensitive hydrogels are considered ideal for applications in the biomedical fields for their biocompatibility, flexibility, tissue-like water content, and reversible gelation property. By adjusting sufficient hydrophilic-hydrophobic balance in block copolymer structure, thermogel's critical gelation temperature can be modified to be near the physiological temperature, which makes it an appealing candidate for in situ gel depot. In this study, we report successful syntheses of novel multiple block copolymer compounds, denoted as dual-stimuli sensitive polymers (DSSPs), by copolymerizing Pluronic^® P104 (7,100 Da) and 2,2-bis(aminoethoxy)propane (BAP) using diisocyanate linkers, L-lysine ethyl ester diisocyanate (DSSP-1) and 1,6-hexamethylene diisocyanate (DSSP-2). Through effective elongation of polymer chain lengths (DSSP-1: 41,760 Da, DSSP-2: 41,230 Da), Pluronic^® P104's reversible thermal gelation properties were enhanced, as demonstrated by lowered critical gelation temperatures (DSSP-1: 36°C, DSSP-2: 38.7°C; 15 wt.%) that is near the physiological temperature. Furthermore, integration of acid-labile BAP allowed rapid pH-dependent degradation of the polymer, which was displayed by gel permeation chromatography (GPC) and release profiles of nile red and irinotecan from polymeric micelles and gels, respectively.