Evolution of silicate bioglass particles as porous microspheres with a view towards orthobiologics.

Although FDA approved and clinically utilised, research on 45S5 Bioglass® and S53P4 including other bioactive glasses continues in order to advance their applicability for a range of alternate applications. For example, rendering these particles porous would enable incorporation of varying biological payloads (i.e. cells, drugs and growth factors) and making them spherical would enhance their flow properties enabling delivery to target sites via minimally invasive injection procedures. This paper reports on the manufacture of solid (non-porous; SGMS) and highly porous microspheres (PGMS) with large external pores and fully interconnected porosity from bioactive silicate glass formulations (45S5 and S53P4) via a single stage flame spheroidisation process and their physicochemical properties including in vitro biological response. Morphological and physical characterisation of the SGMS and PGMS revealed interconnected porosity up to 65 ± 5%. Mass loss studies comparing between SGMS and PGMS revealed 1.5 times higher mass loss for the PGMS over 28 days. Also, in vitro bioactivity studies using simulated body fluid (SBF) revealed hydroxyapatite (HA) formation at earlier time point for PGMS compared to their SGMS counterparts (i.e day 1 for PGMS and day 3 for SGMS of 45S5). In addition, HA layers were also formed in cell culture media, with the exception of SGMS of 45S5, which revealed CaP formation with a ratio of 1.52-1.78. Direct cell seeding and indirect cell culture studies (via incubation with microsphere degradation products) revealed mouse 3T3 cells were able to grow and undergo osteogenic differentiation in vitro, confirming cytocompatibility of both 45S5 and S53P4 SGMS and PGMS. More importantly and especially for orthobiologic applications, cells were observed to have migrated within the pores of the PGMS. As such, the PGMS developed from these bioactive silicate glasses are highly promising candidate materials for orthobiologics and alternate applications requiring delivery of biologic payloads.

Remineralization and antibacterial/antibiofilm effects of toothpaste containing nanohydroxyapatite and Curcuma aeruginosa extract.

The aim of this study was to evaluate the effect of nanohydroxyapatite (nanoHAP) and Curcuma aeruginosa (C. aeruginosa) toothpastes on tooth remineralization and antibacterial/antibiofilm activity. Remineralization was evaluated by the morphological changes in extracted human premolar teeth following toothpaste application. The antibacterial and antibiofilm activities were evaluated by agar diffusion and microdilution methods, respectively, against S. mutans. Statistical approach was utilized to formulate 20 toothpastes with different concentration of nanoHAP and C. aeruginosa. We observed that the interaction among toothpaste ingredients determined the remineralization and antibacterial/antibiofilm activities. The optimum toothpaste formula (OF1) suggested by the prediction model was shown to induce remineralization and have comparable antibacterial activity to that of the control (chlorhexidine gluconate). Furthermore, the antibiofilm activity of this formula was higher to that of the control. The result obtained indicate that these novel toothpastes have potential in decreasing caries prevalence.

Production of hydrophobic amino acids from biobased resources: wheat gluten and rubber seed proteins.

Protein hydrolysis enables production of peptides and free amino acids that are suitable for usage in food and feed or can be used as precursors for bulk chemicals. Several essential amino acids for food and feed have hydrophobic side chains; this property may also be exploited for subsequent separation. Here, we present methods for selective production of hydrophobic amino acids from proteins. Selectivity can be achieved by selection of starting material, selection of hydrolysis conditions, and separation of achieved hydrolysate. Several protease combinations were applied for hydrolysis of rubber seed protein concentrate, wheat gluten, and bovine serum albumin (BSA). High degree of hydrolysis (>50 %) could be achieved. Hydrophobic selectivity was influenced by the combination of proteases and by the extent of hydrolysis. Combination of Pronase and Peptidase R showed the highest selectivity towards hydrophobic amino acids, roughly doubling the content of hydrophobic amino acids in the products compared to the original substrates. Hydrophobic selectivity of 0.6 mol-hydrophobic/mol-total free amino acids was observed after 6 h hydrolysis of wheat gluten and 24 h hydrolysis of rubber seed proteins and BSA. The results of experiments with rubber seed proteins and wheat gluten suggest that this process can be applied to agro-industrial residues.

Towards plant protein refinery: Review on protein extraction using alkali and potential enzymatic assistance.

The globally increasing protein demands require additional resources to those currently available. Furthermore, the optimal usage of protein fractions from both traditional and new protein resources, such as algae and leaves, is essential. Here, we present an overview on alkaline plant protein extraction including the potentials of enzyme addition in the form of proteases and/or carbohydrolases. Strategic biomass selection, combined with the appropriate process conditions can increase protein yields after extraction. Enzyme addition, especially of proteases, can be useful when alkaline protein extraction yields are low. These additions can also be used to enable processing at a pH closer to 7 to avoid the otherwise severe conditions that denature proteins. Finally, a protein biorefinery concept is presented that aims to upcycle residual biomass by separating essential amino acids to be used for food and feed, and non-essential amino acids for production of bulk chemicals.