Evaluation of physico‐mechanical properties and in vitro biocompatibility of compression molded HDPE based biocomposites with HA/Al₂O₃ ceramic fillers and titanate coupling agents

Abstract

The present article demonstrates how the stiffness, hardness as well as the cellular response of bioinert high-density polyethylene (HDPE) can be significantly improved with combined addition of both bioinert and bioactive ceramic fillers. For this purpose, different amounts of hydroxyapatite and alumina, limited to a total of 40 wt %, have been incorporated in HDPE matrix. An important step in composite fabrication was to select appropriate solvent and optimal addition of coupling agent (CA). In case of chemically coupled composites, 2% Titanium IV, 2-propanolato, tris iso-octadecanoato-O was used as a CA. All the hybrid composites, except monolithic HDPE, were fabri-cated under optimized compression molding condition (140 C, 0.75 h, 10 MPa pressure). The compression molded composites were characterized, using X-ray diffraction, Fourier transformed infrared spectroscopy, and scanning electron microscopy. Importantly, in vitro cell culture and cell viability study (MTT) using L929 fibroblast and SaOS2 osteoblast-like cells confirmed good cytocompatibility properties of the developed hybrid composites.

Injection‐molded high‐density polyethylene–hydroxyapatite–aluminum oxide hybrid composites for hard‐tissue replacement: Mechanical, biological, and protein adsorption behavior

“…At the start, HDPE, HA, and Al 2 O 3 were physically mixed in the presence of 2 wt % coupling agent. In view of our earlier research on the HDPE–HA–Al 2 O 3 system,25 it was decided to load 40 wt % filler (20 wt % HA and 20 wt % Al 2 O 3 ) in polymer matrix. Injection molding was carried out at a barrel temperature of 180°C and a mold temperature of 25°C.…”

“…Inspired by the previous research work, we carried out preliminary studies of chemically coupled HDPE–HA–Al 2 O 3 composites using the compression‐molding technique 25. The objective was to enhance the interfacial bonding between the polymer and ceramic phases with coupling agents to promote molecular bonding and, consequently to improve interfacial adhesion 26, 27…”

In vitro cytotoxicity and in vivo osseointergration properties of compression‐molded HDPE‐HA‐Al2O3 hybrid biocomposites

“…On the basis of the physical property combination, as reported in our earlier work, 23 HDPE-40 wt % HA and HDPE-20 wt % HA-20 wt % Al 2 O 3 were selected for this study. HDPE has been used as a matrix of the composite.…”

“…For both in vitro and in vivo biocompatibility property assesment, HDPE-40 wt % HA (CS3) and HDPE-20 wt % HA-20 wt % Al 2 O 3 (CS7) with 2 wt % titanate coupling agent were used and the selection of these two compositions was done on the basis of optimized mechanical and biological properties, as reported in our earlier publication. 23 The specimens were compounded at a constant pressure of 10 MPa and at a temperature of 140 C for 0.75 h on a commercial compression-molding unit. While in vitro assays were performed on composite particle eluates, the in vivo implantation was carried out with bulk compressionmolded composites.…”

“…To overcome this problem, one of the major approaches is to develop polymer-ceramic based bone analogue composite. As part of our ongoing research in the area of biomaterials, 17,23 chemically coupled HDPE-HA-Al 2 O 3 composites with a desired combination of mechanical properties and good in vitro cytocompatibility are recently being developed.…”