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CitationTierney CM, Jaasma MJ, O'Brien FJ. Osteoblast activity on collagen-GAG scaffolds is affected by collagen and GAG concentrations. • to copy, distribute, display, and perform the work.• to make derivative works. Under the following conditions:• Attribution -You must give the original author credit.• Non-Commercial -You may not use this work for commercial purposes.• Osteoblast activity on collagen-GAG scaffolds is affected by collagen and GAG concentrations AbstractOptimisation of a tissue engineering scaffold for use in bone tissue engineering requires control of many factors such as pore size, porosity, permeability and, as this study shows, the composition of the matrix. The collagen and GAG content of the collagen-GAG scaffold variants were fabricated by varying the collagen and GAG content of the scaffold. Scaffolds were seeded with MC3T3 osteoblasts and cultured for up to 7 days.During the culture period, osteoblastic activity was evaluated by measuring metabolic activity, cell number and spatial distribution. Collagen and GAG concentrations both affected osteoblast viability, proliferation and spatial distribution within the scaffold.Scaffolds containing 1% collagen (w/v) and 0.2% GAG (w/v) were found to have a porosity of ~99%, high cell metabolic activity and number and cell infiltration up to 7 days. Taken together, these results indicate the need to tailor the parameters of a biological substrate for use in a specific tissue application, in this case bone tissue engineering.

Osteoporosis is a global health problem characterized by low bone mass and an increase in bone fragility. It is now well accepted that dietary factors play a central role in bone development and health. Diet that lacks adequate minerals is considered to be a risk factor for osteoporosis. The food supplement, Aquamin, is a natural, multi‐mineral derived from the red algae Lithothamnion corallioides, rich in calcium, magnesium and 72 other trace minerals. The aim of this study was to evaluate the effect of Aquamin on osteoblastic behaviour and mineralisation in a pre‐osteoblastic cell line. Cell number and metabolic activity were assessed using Hoescht DNA and AlamarBlue assays respectively. Osteogenic differentiation was measured using an alkaline phosphatase assay while mineralisation was determined using von Kossa and alizarin red staining. It is reported here that Aquamin promotes increased mineralisation in osteoblast cell culture. These data suggest that the nutritional supplement Aquamin plays an important role in promoting bone formation and may be useful in treating bone diseases such as osteoporosis. Copyright © 2011 John Wiley & Sons, Ltd.

Objectives Topical nasal steroids are a common treatment intervention for olfactory dysfunction. Penetration of topical treatment to the olfactory cleft (OC), such as nasal drops, is greatly dependent on the position of the head when the treatment is administered. We aimed to examine the penetrance of nasal drops to the OC in two different head positions: the Mygind (lying head back) position and the Kaiteki position. Design and Setting The specimens were firstly positioned in Mygind, and thereafter in Kaiteki positions. Nasal drops mixed with blue food dye were administered into the nostrils in each of the head position. Endoscopic videos were recorded, and two blinded observers scored the extent of olfactory cleft penetration (OCP) using a 4‐point scale (0 = none, 3 = heavy). Participants Twelve fresh‐frozen cadaver specimens. Main outcome measures Penetration of the dye into the OC. Results The mean score of nasal drops penetrance to the OC in the Mygind position was 1.34 (standard deviation, SD = 0.92), as compared to 1.76 (SD = 0.65) in the Kaiteki position. The difference in the OCP score between the two groups was not statistically significant (P > .05). Conclusion Both Mygind and Kaiteki head positions are reasonable options for patients considering topical nasal drops for olfaction impairment. The preference of one position over the other should be determined by patient's preference and comfort.