This paper reports on microneedles produced from biopolymer films extracted from fish scales of tilapia (Oreochromiss sp) using micromoulding technique. Evaluation of the properties of polypeptide films prepared from the fish scales gave refractive index (1.34), Protein concentration (78%), ash content (1.6%) at (22%) moisture content. The microneedles successfully inserted into artificial skin models and imaging using digital camera showed microneedles remained intact when inserted and when removed from the skin model. Microneedles also successfully inserted into porcine skin and were shown to dissolve gradually at 0s, 60s, 120s and 180s after insertion. Microneedles containing methylene blue as model drug were also produced and successfully pierced porcine skin. 3D finite element (FEM) simulations were carried out using the measured mechanical properties of the biopolymer films (Young's modulus 0.23N/mm2and tensile strength 1.8105N/mm2) to evaluate the stress distribution on various dimensions of the fish scale derived microneedles and hence, their ability to withstand force necessary to pierce the skin without fracture. Results from mechanical analysis using FEM showed that microneedles with tip radius between 10 and 100µm could withstand up to 0.12N of force per microneedle without fracture, which is indicated when the stress at the tip of the microneedle exceeds the ultimate stress of the material of fabrication. Using skin insertion tests and finite element simulations this study provides evidence that microneedles fabricated from fish scale biopolymer can effectively pierce and degrade into skin and therefore are good candidate for transdermal applications.
Aims:The study investigated the suitability of three agricultural wastes commonly found in Nigeria namely Pineapple leaf (Ananas cosmosus), banana peduncle and banana leaf (Musa sapientum) for their pulp and paper-making potentials. Study Design: Fresh Musa sapientum waste and pineapple leaves were obtained from banana plantation and local pineapple processing firms around the vicinity of the Institute. The samples were processed, characterized for fibre properties, pulped and converted to handsheets. The properties of the fibre and paper were compared to the properties of non-wood and woody biomass found in Nigeria.
One of the main reasons for the continued increase in the deficit of affordable housing in Nigeria is the high cost of brick made from sand and ordinary Portland cement (OPC). Finding a replacement for cement to assure sustainability is crucial as the raw materials used in making cements which are naturally occurring are depleting. Rice husk was milled and sieved to reduce the size to 0.020 mm. The moisture content of the rice husk was 9.98%, bulk density was 609.61g cm -3 and the ash content was 18.74%. Rice husk was wetted for 3, 6, 9, 12, 15 and 21 h and mixed with slaked lime at the ratios of 1:1, 3:1, 2:3 and 3:2. The composite was molded in cylindrical and rectangular mold using mechanical and hydraulic press. The compressive strength (CS) (N/mm 2 ) was tested at ages of 7, 14 and 21 days. The results show higher compressive strength in 1:1 as the bricks ages and also greater strength when wetted for 15 h. For 15 h wetting, 1:1 had CS (N/mm 2 ) of 2.59, 6.07 and 11.23. If well optimized, rice husk can be an excellent material for brick production thereby presenting a good alternative to OPC.
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