PLGA Microspheres of hGH of Preserved Native State Prepared Using a Self-Regulated Process.

The challenges of formulating recombinant human growth hormone (rhGH) into sustained-release polymeric microspheres include two mutual causal factors, protein denaturing by the formulation process and severe initial burst release related with relative high dose. The stabilizers to protect the proteins must not evoke osmotic pressure inside the microspheres, and the contact of the protein with the interface between water and organic solution of the polymer must be minimized. To meet these criteria, rhGH was pre-formulated into polysaccharide particles via an aqueous-aqueous emulsion in the present study, followed by encapsulating the particles into microspheres through a self-regulated process to minimize the contact of the protein with the water-oil interface.

Assembling structurally customizable synthetic carriers of siRNA through thermodynamically self-regulated process.

This study demonstrates that our previously reported polywraplex, a synthetic siRNA carrier consisting of a uni-molecular polyplex core of customizable size and a self-assembled tri-block copolymer envelop, may be constructed using dendrimers as the crosslinking junctions. Replacing the branched low molecular weight PEI with polyamidoamine (PAMAM) dendrimer in the zeta potential regulated polymerization resulted in the similar network structured cationic polymer with electron microscopically visible crosslinking junctions. This visibility may offer a convenient way to characterize the molecular structure of the rationally designed networked siRNA-packing cationic polymer without altering its chemical properties and biologic functions.

Effect of Polyethylene Glycol on Properties and Drug Encapsulation-Release Performance of Biodegradable/Cytocompatible Agarose-Polyethylene Glycol-Polycaprolactone Amphiphilic Co-Network Gels.

We synthesized agarose-polycaprolactone (Agr-PCL) bicomponent and Agr-polyethylene glycol-PCL (Agr-PEG-PCL) tricomponent amphiphilic co-network (APCN) gels by the sequential nucleophilic substitution reaction between amine-functionalized Agr and activated halide terminated PCL or PCL-b-PEG-b-PCL copolymer for the sustained and localized delivery of hydrophilic and hydrophobic drugs. The biodegradability of the APCNs was confirmed using lipase and by hydrolytic degradation. These APCN gels displayed good cytocompatibility and blood compatibility.

Degradable/cytocompatible and pH responsive amphiphilic conetwork gels based on agarose-graft copolymers and polycaprolactone.

Amphiphilic conetwork (APCN) gels have emerged as an important class of biomaterials due to their diverse applications. APCN gels based on biocompatible/biodegradable polymers are useful for controlled release and tissue engineering applications. Herein, we report a facile synthesis of APCN gel films by click type sequential nucleophilic substitution reaction between pendent tertiary amine groups of agarose-g-poly(methyl methacrylate)-b(co)-poly(2-dimethylamino)ethyl methacrylate [Agr-g-PMMA-b(co)-PDMA] copolymers and activated benzyl chloride groups of polychloromethyl styrene or benzyl methyl chloride terminated polycaprolactone.

Microwave assisted preparation of n-butylacrylate grafted chitosan and its application for Cr(VI) adsorption.

Biopolymers such as chitosan possess excellent properties suited for varied applications. In this work, we describe a novel microwave assisted method for the preparation of n-butylacrylate grafted chitosan adsorbent and its utility for the adsorption of chromium(VI). A 3 min irradiation time was enough to prepare the adsorbent, and techniques such as FT-IR, powder XRD, SEM and EDS were used for comprehensive characterization.