Mixed-Phase Ion-Exchangers from Waste Amber Container Glass.

This study investigated the one-pot hydrothermal synthesis of mixed-phase ion-exchangers from waste amber container glass and three different aluminium sources (Si/Al = 2) in 4.5 M NaOH(aq) at 100 °C. Reaction products were characterised by X-ray diffraction analysis, Fourier transform infrared spectroscopy, 27Al and 29Si magic angle spinning nuclear magnetic resonance spectroscopy and scanning electron microscopy at 24, 48 and 150 h. Nitrated forms of cancrinite and sodalite were the predominant products obtained with reagent grade aluminium nitrate (Al(NO3)3∙9H2O). Waste aluminium foil gave rise to sodalite, tobermorite and zeolite Na-P1 as major phases; and the principal products arising from amorphous aluminium hydroxide waste were sodalite, tobermorite and zeolite A. Minor proportions of the hydrogarnet, katoite, and calcite were also present in each sample. In each case, crystallisation was incomplete and products of 52, 65 and 49% crystallinity were obtained at 150 h for the samples prepared with aluminium nitrate (AN-150), aluminium foil (AF-150) and amorphous aluminium hydroxide waste (AH-150), respectively. Batch Pb2+-uptake (~100 mg g-1) was similar for all 150-h samples irrespective of the nature of the aluminium reagent and composition of the product. Batch Cd2+-uptakes of AF-150 (54 mg g-1) and AH-150 (48 mg g-1) were greater than that of AN-150 (36 mg g-1) indicating that the sodalite- and tobermorite-rich products exhibited a superior affinity for Cd2+ ions. The observed Pb2+- and Cd2+-uptake capacities of the mixed-product ion-exchangers compared favourably with those of other inorganic waste-derived sorbents reported in the literature.

Bioprinting and Preliminary Testing of Highly Reproducible Novel Bioink for Potential Skin Regeneration.

Three-dimensional (3D) bioprinting is considered as a novel approach in biofabricating cell-laden constructs that could potentially be used to promote skin regeneration following injury. In this study, a novel crosslinked chitosan (CH)-genipin (GE) bioink laden with keratinocyte and human dermal fibroblast cells was developed and printed successfully using an extruder-based bioprinter. By altering the composition and degree of CH-GE crosslinking, bioink printability was further assessed and compared with a commercial bioink. Rheological analysis showed that the viscosity of the optimised bioink was in a suitable range that facilitated reproducible and reliable printing by applying low pressures ranging from 20-40 kPa. The application of low printing pressures proved vital for viability of cells loaded within the bioinks. Further characterisation using MTT assay showed that cells were still viable within the printed construct at 93% despite the crosslinking, processing and after subjecting to physiological conditions for seven days. The morphological study of the printed cells showed that they were mobile within the bioink. Furthermore, the multi-layered 3D printed constructs demonstrated excellent self-supportive structures in a consistent manner.