Trifunctional Copolymer Research Articles

Zwitterion and N-halamine functionalized cotton wound dressing with enhanced antifouling, antibacterial, and hemostatic properties

With emerging needs of wound care management, a multi-functional wound dressing is needed. To prevent infection and reduce patient suffering, antibacterial efficacy against a broad-spectrum of bacteria plus robust antifouling are among the most preferred properties. In this study, a wound dressing was created with antibacterial and anti-fouling capabilities is presented. The approaches used a synthesized tri-functional copolymer comprised of an N-halamine precursor moiety, a marine-inspired surface binding dopamine moiety, and a zwitterionic anti-adhesion moiety bonded onto a commercial cotton gauze. The resulting HaloCare™ wound dressing demonstrated >99.99 % inactivation within 5 min against E. coli and a panel of ESKAPE pathogens plus achieved 98.77 % reduction of non-specific protein binding. HaloCare was also shown to be compatible with hemostatic agents without impacting hemostatic efficacy. HaloCare shows great potential particularly in traumatic injury events as an infection preventing and hemostatic wound management system.

Non-invasive topical drug delivery to spinal cord with carboxyl-modified trifunctional copolymer of ethylene oxide and propylene oxide

In this study the effect of oxidative modification on micellar and drug delivery properties of copolymers of ethylene oxide (EO) and propylene oxide (PO) was investigated. Carboxylated trifunctional copolymers were synthesized in the reaction with chromium(VI) oxide. We found that carboxylation significantly improved the uniformity and stability of polymeric micelles by inhibiting the microphase transition. The cytotoxicity of copolymers was studied in relation to their aggregative state on two cell types (cancer line vs. primary fibroblasts). The accumulation of rhodamine 123 in neuroblastoma SH-SY5Y cells was dramatically increased in the presence of the oxidized block copolymer with the number of PO and EO units of 83.5 and 24.2, respectively. The copolymer was also tested as an enhancer for topical drug delivery to the spinal cord when applied subdurally. The oxidized copolymer facilitated the penetration of rhodamine 123 across spinal cord tissues and increased its intraspinal accumulation. These results show the potential of using oxidized EO/PO based polymers for non-invasive delivery of protective drugs after spinal cord injury.

Intracellular delivery of VEGF165 encoding gene therapeutic using trifunctional copolymers of ethylene oxide and propylene oxide

New type of copolymers of propylene oxide and ethylene oxide was assessed for promoting delivery of plasmid DNA based gene therapeutics. Lipid-like trifunctional copolymers (TFCs), with both random or diblock structures and relatively low hydrophilic–lipophilic balance, were studied and compared with linear Pluronic™ L61. Structure-dependent relationships for micelle-forming, cytotoxic and hemolytic properties of these copolymers were revealed. The TFC with the mean number of propylene oxide and ethylene oxide units of 83.5 and 24.2, respectively, exhibited relatively low adverse effects in vitro. The latter TFC interacted with plasmid DNA–polyethyleneimine complexes and improved their intracellular delivery. Furthermore, this TFC efficiently promoted the transfection of dermal fibroblasts with VEGF165-encoding Neovasculgen® plasmid DNA, which has been clinically used for the therapeutic angiogenesis. Our findings demonstrated for the first time that TFCs are promising for the polymer-mediated delivery of gene therapeutics.

Evaluation of Cell Membrane-Modulating Properties of Non-Ionic Surfactants with the use of Atomic Force Spectroscopy

Analytical possibilities of atomic force spectroscopy (AFS) in liquid were studied upon interaction of membranotropic polymers with the plasma membrane of human cells. Topographical visualization of tightly adherent dermal fibroblasts, but not relatively soft prostate cancer (PC-3) cells, was achieved using a conventional triangular cantilever. A microsphere-based probe has been developed and applied for AFS analysis of micromechanical properties of PC-3 cells. Non-ionic block copolymers of ethylene oxide and propylene oxide, bi-functional Pluronic® L61, and glycerol-based tri-functional copolymer (TFC) were studied as potential modulators of cellular membranes and drug delivery systems as reported by Bondar et al. (Int. J. Pharm. 461(97), 104, 2014). As indicated by dynamic light scattering and fluorescent techniques, Pluronic® L61 and TFC were adsorbed onto the cell surface and inserted into the plasma membrane in different extent. Analysis of AFS curves for surfactant-treated PC-3 cells showed that both Pluronic® L61 and TFC decreased the Young’s modulus of cellular surface by almost 1.6 and 2 times, respectively. This is in accordance with the ability of amphiphilic polymers of decreasing the microviscosity of cellular membrane and promoting intracellular drug uptake as shown previously by Bondar et al. (Int. J. Pharm. 461(97), 104, 2014). Our results are of particular interest for the characterization of interaction of living cells with amphiphilic polymer-based nanocarriers and drug formulations using AFS and other surface-sensitive techniques.

Study on the Tri-Functional Copolymer Containing 1,3,4-Oxadiazole, Carbazole and Terbium Complex

A novel tri-functional copolymer P1 containing hole transporting units, electron transporting units and terbium complex units was synthesized via radical copolymerization. It was characterized by DSC, TGA, Fluorescence, CV and I-V data test. The results showed that the copolymer P1 was capable of pure green emission in the solid state under UV excitation and had potential application in the memory or light-emitting device.