Zhao Kongyin

Electrospun carboxyl multi-walled carbon nanotubes grafted polyhydroxybutyrate composite nanofibers membrane scaffolds: Preparation, characterization and cytocompatibility

Electrospun polyhydroxybutyrate (PHB)/carboxyl multi-walled carbon nanotubes grafted polyhydroxybutyrate (CMWCNT-g-PHB) composite nanofibers scaffolds were fabricated by electrospinning technology. The grafted product CMWCNT-g-PHB was prepared by condensation reactions between the carboxyl groups of CMWCNT and hydroxyl groups of PHB molecules and characterized by FTIR, XRD, XPS, TG and TEM measurements. The surface morphology, hydrophilicity and tensile mechanical properties of the electrospun PHB/CMWCNT-g-PHB composite nanofibers membrane scaffolds were investigated. The values of tensile strength, breaking elongation rate, initial modulus and fracture energy of the composite nanofibers scaffolds can reach to 4.64MPa, 255.59%, 88MPa and 109.73kJ/m2, respectively. The biodegradability and cytocompatibility of the electrospun composite nanofibers scaffolds were preliminarily evaluated. The as-prepared electrospun PHB/CMWCNT-g-PHB composite nanofibers scaffolds with the characteristics of large specific area, high porosity, good biodegradability and cytocompatibility as well as sufficient mechanical properties should be more promising in the field of tissue engineering scaffolds and biological medicine.

Protein molecularly imprinted polysiloxane prepared using calcium silicate/calcium alginate composite membrane as the matrix

Calcium silicate/calcium alginate composite hydrogel membrane (CaSiO3/CaAlg) was prepared by cross-linking the mixture of calcium silicate and sodium alginate with CaCl2 solution. Then the Haemoglobin (Hb) molecularly imprinted polysiloxane (MIP) was synthesized using CaSiO3/CaAlg composite hydrogel membrane as the matrix to adsorb Hb (the template), using Ethylenetri(β-methoxy)ethyoxysilane (KH-570) and γ-amidopropyltriethyoxysilane (KH-550) as functional monomers. The surface morphology and the thermal performance of the MIP membrane were characterized by scanning electron microscope (SEM) and thermogravimetric (TG) analysis. The surface contact angle and the swelling properties of the MIPs prepared with different silanes were studied. The adsorption properties of MIP and non-imprinted polysiloxane (NIP) were evaluated and the results showed that MIP membrane exhibited a significant improvement in terms of rebinding capacity for Hb compared with NIP. The MIP membrane could selectively recognize the template protein. The curves of Hb adsorption for Both MIP and NIP membrane are more in line with the Langmuir adsorption model. The adsorption rate of the MIP prepared in this paper was fast, the adsorption quantity was big and the MIP membrane was easy to be used. The MIP membrane could be widely used in protein separation and analysis, protein control release and biomedical engineering.

Preparation and characterization of proteinmolecular imprinted calcium alginate hydrogel film with controllablethickness

Bovine serum albumin (BSA) imprinted calcium alginate (CaAlg MIP) hydrogel film was prepared using BSA as template molecule, sodium alginate (NaAlg) as the functional monomer, and CaCl2 as the ionic cross-linker. The thickness of the film was controlled by a glass rod enlaced with brass wires. The relationship between copper wire diameter and the thickness of CaAlg MIP was investigated. SEM, laser scanning confocal microscope and 3D ultra-depth three-dimensional microscope were used to characterize the CaAlg MIP. The mechanical properties of the wet CaAlg MIP prepared with different concentrations of NaAlg were investigated. Circular dichroism (CD) was used to characterize the conformation of the eluted BSA. The influence of different thickness and different eluants on the adsorption capacity of CaAlg MIP was discussed. The results showed that CaAlg MIP adsorbed more BSA than CaAlg NIP. There was no change of the conformation of protein during the preparing and eluting process. The CaAlg MIP can be prepared by a fast, low-cost and environmental friendly method in aqueous solution in the absence of any toxic surfactant or organic solvent, which would find its potential applications in the fields of cell culture and tissue engineering.