In situ fabrication of PHEMA–BSA core–corona biohybrid particles

Abstract

Polymer-protein core-corona particles can be used as multifunctional platforms in biological and medical applications. In this research, we prepared poly(2-hydroxyethyl methacrylate)-bovine serum albumin (PHEMA-BSA) core-corona particles by the ''grafting from'' method. In order to prepare the particles, activators generated by electron transfer for atom transfer radical polymerizations (AGET ATRP) of HEMA initiated by a BSA macroinitiator were performed. The polymerizations were conducted in the presence of ppm amounts of transition metal catalyst and ascorbic acid. Transmission electron microscopy, atomic force microscopy, dynamic light scattering and x-potential measurements were used to characterize the core-corona particles. The average size and x-potentials of the particles are strongly dependent on the amounts of BSA used in AGET ATRP. The secondary structure and bioactivity of the protein molecules in the coronae of the particles were studied. In vitro cytotoxicity assays and cell uptake assays indicate that the biohybrid particles are nontoxic and can be internalized into the cells. The polymer-protein core-corona particles will find applications in drug delivery and biomedical imaging.

Preparation of biomolecule-polymer conjugates by grafting-from using ATRP, RAFT, or ROMP

“…Liu, Zhao, and coworkers prepared core-corona type nanoparticle with a BSA decorated corona and a cross-linked poly(HEMA) core. [81] The BSA-macroinitiator was prepared through disulfide exchange with a PDS-functionalized ATRP initiator to modify Cys-34 on BSA. Polymerization from the BSA-macroinitiator was carried out in aqueous solutions using typical AGET ATRP conditions in the presence of HEMA and the cross-linker N,N'-methylene diacrylamide.…”

“…These examples illustrate the utility of AGET ATRP grafting from in preparing more complex architectures with retention of protein structure and activity. [81] Matyjaszewski and coworkers systematically screened conditions to polymerize PEGMA from BSA using ATRP in aqueous conditions resulting in conjugates with good control over molecular weight and dispersity. [71] Conditions were first screened with traditional ATRP methods, then AGET ATRP was then investigated to prepare BSA conjugates.…”

Supramolecular Assembly of a Molecularly Engineered Protein and Polymer

“…BSA is known to exhibit esterase‐like activity, which is often demonstrated by its ability to trigger enzymatic hydrolysis of 4‐nitrophenyl acetate (NPA) to generate 4‐nitrophenol. However, in some examples of covalent protein–polymer conjugates, the activity decreases as a result of immobilisation . To investigate whether BSA remains intact in the closely packed assembly of NDI‐BSA or its supramolecular conjugate with NDI‐PNIPAM, the NPA assay was performed by measuring the absorbance of 4‐nitrophenol ( λ =405 nm) by means of UV/Vis spectroscopy (Figure a; for reaction kinetics, see Figure S13 in the Supporting Information).…”

Block copolymer micelles with enzyme molecules at the interfaces

“…Our calculation result indicated that on average there were around 3.8 thiol groups on a PPL molecule. Pyridyl disulfide groups are able to have highly efficient thiol‐disulfide exchange reactions with thiol‐bearing molecules . PPL‐SH were conjugated to the block polymer chains by the exchange reaction under mild condition.…”