Preparation and characterization of polyurethane/polyethylene glycol/copper nanocomposite / 生物医学工程学杂志

A novel Cu-IUDs material, PU/PEG/Cu nanocomposite, was prepared by melt blending method with thermoplastic polyurethane (PU) as the matrix, with polyethylene glycol (PEG) as a hydrophilic modifier, and with nanometer particles of copper as active matter instead of copper wire or copper tube. The structure, morphology, mechanical properties, thermal stability and water absorption were investigated by using FT-IR, XRD, SEM and so on. The results indicated that the nanometer particles of copper were uniformly dispersed in the matrix in PU/PEG/ Cu nanocomposites. It can be seen that the water absorption ability of this nanocomposite was obviously improved while mechanical properties and thermal stability were at high levels. These results provided a good basis for the studies on the cupric ions release of the nanocomposites in future.

Synthesis and properties of poly(hydroxyethyl methacrylate) hydrogel for IOL materials / 生物医学工程学杂志

Poly (hydroxyethyl methacrylate) (PHEMA) hydrogel for intraocular lens (IOL) materials was synthesized by solution polymerization using 2-hydroxyethyl methacrylate (HEMA) as raw material, ammonium persulfate and sodium pyrosulfite (KPS/SMBS) as catalyst, and trietyleneglycole dimethacrylate (TEGDMA) as cross-linking additive. Effects of reaction time, temperature, dosage of catalyst and cross-linking additive on mechanical strength and the equilibrium water content (EWC) of the PHEMA hydrogel were systematically investigated and their structure and optical property were also characterized. The experimental results showed that the optimum conditions for preparing PHEMA hydrogel are: catalyst 0.5 wt%, cross-linking additive 1.0 wt%, reaction temperature 40 degrees C, reaction time 36 h. Under the optimum conditions, the tensile strength of PHEMA hydrogel prepared is as high as 0.57 MPa, hardness of Shore A is 23.0, EWC is over 40%, and light transmittance is over 97%.

Development of biodegradable and bioabsorbable bone-repaired materials / 生物医学工程学杂志

This paper reviews recent work on biodegradable and bioabsorbable materials, including macromolecular, inorganic, and compound materials which have been used as bone-repaired devices. The properties and uses of poly(lactic acid), chitin and tricalcium phosphate are expounded. At the same time, we discuss the trend in the development of biodegradable and bioabsorbable bone-repaired materials. In our opinion, the development of biodegradable and bioabsorbable bone-repaired materials forcuses on the composite of different materials, especially the composite of BMP and MSCs; on the improvement of the mechanical properties of materials; and on the search for new suitable materials.

Effect of moulding and extruding conditions on mechanical properties of poly(D,L-lactide) and MDI chain-extending poly(D,L-lactide)/hydroxyapatite composite / 生物医学工程学杂志

In this paper, poly(D,L-lactide) (PDLLA), MDI chain-extending poly(D,L-lactide) (PDLLA/MDI) and MDI chain-extending poly(D,L-lactide)/hydroxyapatite composite (PDLLA/HA/MDI) were prepared respectively and the effects of moulding and extruding conditions on their mechanical properties were also investigated. At the optimal conditions, bending strength of PDLLA and PDLLA/MDI is 35.1 MPa and 51.3 MPa, respectively, and their bending modulus is 2413.6 MPa and 1830.9 MPa, respectively. Bending strength of PDLLA/HA and PDLLA/HA/MDI is 31.2 MPa and 55.4 MPa, respectively, and their bending modulus is 1735.0 MPa and 2068.5 MPa, respectively. These results have shown that the mechanical properties of PDLLA/MDI and PDLLA/HA/MDI have enhanced significantly by MDI chain-extending.