This study aims to pre-assess the in vitro and in vivo biocompatibility of poly(vinyl alcohol)-carboxylmethyl-chitosan-poly(ethylene glycol) (PCP) scaffold. PCP was lyophilised to create supermacroporous structures. 3-(4, 5-dimethyl-thiazol-2yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and immunohistochemistry (IHC) were used to evaluate the effectiveness of PCP scaffolds for chondrocytes attachment and proliferation. The ultrastructural was assessed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Extracellular matrix (ECM) formation was evaluated using collagen type-II staining, glycosaminoglycan (GAG) and collagen assays. Histological analysis was conducted on 3-week implanted Sprague-Dawley rats. The MTT, IHC, SEM and TEM analyses confirm that PCP scaffolds promoted cell attachment and proliferation in vitro. The chondrocyte-PCP constructs secreted GAG and collagen type-II, both increased significantly from day-14 to day-28 (P < 0.05). PCP scaffolds did not elicit any adverse effects on the host tissue, but were partially degraded. These results suggest that supermacroporous PCP is a biocompatible scaffold for clinical applications.

Objective: This preliminary study aims to determine the differentially expressed proteins from chondrogenic differentiated multipotent stromal cells (cMSCs) in comparison to undifferentiated multipotent stromal cells (MSCs) and adult chondrocytes (ACs).Methods: ACs and bone marrow-derived MSCs were harvested from New Zealand White rabbits (n = 3). ACs and cMSCs were embedded in alginate and were cultured using a defined chondrogenic medium containing transforming growth factor-beta 3 (TGF-β3). Chondrogenic expression was determined using type-II collagen, Safranin-O staining and glycosaminoglycan analyses. Two-dimensional gel electrophoresis (2-DE) was used to isolate proteins from MSCs, cMSCs and ACs before being identified using liquid chromatography-mass spectrometry (LC-MS). The differentially expressed proteins were then analyzed using image analysis software.Results: Both cMSCs and ACs were positively stained with type-II collagen and safranin-O. The expression of glycosaminoglycan in cMSCs was comparable to AC at which the highest level was observed at day-21 (p>0.05). Six protein spots were found to be most differentially expressed between MSCs, cMSCs and ACs. The protein spots cofilin-1 (CFL1) and glycealdehyde-3-phosphate dehydrogenase (GAPD) from cMSCs had expression levels similar to that of ACs whereas the others (ie. MYL6B, ALDOA, TAGLN2, EF1-alpha), did not match the expression level of ACs.Conclusion: Despite having similar phenotypic expressions to ACs, cMSCs expressed proteins which were not typically expected. This may explain the reason for the unexplained lack of improvement in cartilage repair outcomes reported in previous studies.

Chinese knotweed (Persicaria chinensis) is of ecological and economic importance as a high-risk invasive species and a traditional medicinal herb. However, the insects associated with P. chinensis pollination have received scant attention. As a widespread invasive plant we would expect P. chinensis to be associated with a diverse group of insect pollinators, but lack of taxonomic identification capacity is an impediment to confirm this expectation. In the present study we aimed to elucidate the insect pollinators of P. chinensis in peninsular Malaysia using DNA barcoding. Forty flower visitors, representing the range of morphological diversity observed, were captured at flowers at Ulu Kali, Pahang, Malaysia. Using Automated Barcode Gap Discovery, 17 morphospecies were assigned to 23 species representing at least ten families and four orders. Using the DNA barcode library (BOLD) 30% of the species could be assigned a species name, and 70% could be assigned a genus name. The insects visiting P. chinensis were broadly similar to those previously reported as visiting Persicaria japonica, including honey bees (Apis), droneflies (Eristalis), blowflies (Lucilia) and potter wasps (Eumedes), but also included thrips and ants.

In vitro cellular proliferation and the ability to undergo multilineage differentiation make bone marrow-derived multipotent stromal cells (MSCs) potentially useful for clinical applications. Several methods have been described to isolate a homogenous bone marrow-derived MSCs population; however, none has been proven most effective, mainly due to their effects on proliferation and differentiation capability of the isolated cells. It is hypothesized that our newly established total cell pooling method may provide a better alternative as compared to the standard isolation method (density gradient centrifugation method). For the total cell pooling method, MSCs were isolated from rabbit bone marrow and were subsequently cultured in the growth medium without further separation as in the standard isolation method. The total cell pooling method was 65 min faster than the standard isolation method in completing cell isolation. Nevertheless, both methods did not differ significantly in the number of primary viable cells and population doubling time in the cultures (p > 0.05). The isolated cells from both methods expressed CD29 and CD44 markers, but not CD45 markers. Furthermore, they displayed multilineage differentiation characteristics of chondroblasts, osteoblasts, and adipocytes. In conclusion, both methods provide similar efficiency in the isolation of rabbit bone marrow-derived MSCs; however, the total cell pooling method is technically simpler and more cost effective than the standard isolation method.

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