Synthesis of polycaprolactone-hydroxyapatite (PCL-HA) biodegradable nanofibres via an electrospinning technique for tissue engineering scaffolds

The interest in biodegradable polymer nanofibres with tissue cell regeneration potential has increased in recent years. However, there are issues in the development of scaffolding to provide a favourable environment for cell proliferation and attachment. Such issues can be overcome by the addition of hydroxyapatite (HA), which is widely used in biomaterial applications. Biodegradable nanofibres of polycaprolactone (PCL) and hydroxyapatite (HA) have been produced by electrospinning. In this study, PCL was mixed with HA to synthesise nanofibres by single nozzle electrospinning. Furthermore, PCL-HA nanofibres were mixed with fibronectin to investigate the effect of adhesion of fibronectin to the surface of the PCL-HA nanofibres. The structure and morphology of nanofibres were determined by scanning electron microscopy (SEM), the chemical properties of nanofibres were analysed by Fourier transform infrared (FTIR), and the diameter and adhesive force of nanofibers and fibronectin were determined by an atomic force microscope (AFM). The SEM examination revealed the formation of cylindrical and smooth nanofibres with dense fibre networks when 10% HA was used, as HA can generate fibre. FTIR analysis indicated the presence of PCL and HA inside the nanofibres produced by electrospinning. The AFM examination showed that the PCL-HA nanofibres with 100 μg/ml of fibronectin gives the highest adhesion force which is important for the scaffold to resist the force from the external environment. This outcome resulted indicates that the PCL-HA nanofibers with fibronectin are promising for tissue engineering scaffold application. Hence, further investigations are needed to ensure the compatibility of living cells to survive and grow on the PCL-HA nanofibrous mats

Hydroxychloroquine for COVID-19: a single center, retrospective cohort study

Introduction: The outbreak of coronavirus disease (COVID-19) in December 2019 called for a rapid solution, leading to repurposing of existing drugs. Due to its immunomodulatory effect and antiviral properties, hydroxychloroquine (HCQ) has been used in early 2020 for treatment of COVID-19 patients. This study was conducted to evaluate the treatment outcome of HCQ monotherapy in Malaysia. Methods: A retrospective cohort study was conducted in COVID-19 ward in Hospital Kuala Lumpur (HKL), from March to April 2020. A total of 446 COVID-19 patients were recruited, only 325 patients were finally included for analysis. Statistical analysis was done using SPSS, with a significant value set at p<0.05. Results: The mean age of the patients were 38.5 ±15.5. They were majority male, (n=210, 64.6%) Malaysian (n=239, 73.5%) and Malay ethnicity (n=204, 62.8%). Ninety-one (28%) patients received HCQ monotherapy. HCQ monotherapy was associated with worse outcome (OR: 10.29, 95% CI 1.17-90.80). There was a significant difference in mean length of stay between those with and without HCQ treatment (t323=5.868, p<0.001, 95% CI, 2.56-5.31). The average length of stay for HCQ treated group was 3.84 days longer than those without treatment. 6.6% of the patient receiving HCQ monotherapy encountered adverse drug effects. Conclusion: Similar to study reported worldwide, our study demonstrated that HCQ did not improve length of stay and the outcome of COVID-19 patients

Chitin and Chitosan preparation from Malaysian Black Soldier Fly biomass: a preliminary study

Chitin, as well as its deacetylated variant chitosan, has a wide range of applications in biomedical, agricultural, environmental and food industries. Currently, chitin is commercially produced from crustacean shells rather than fungal or insect sources. In this study, chitin from different lifecycle phases of the black soldier fly (Hermetia illucens) (BSF) was extracted and deacetylated into chitosan. Both BSF chitin and chitosan were further subjected to FTIR analysis. The chitin extraction yield % was obtained according to the following order: cocoon>larvae>prepupae. On the other hand, the yield of chemical deacetylation of chitin into chitosan showed a different trend: larvae>prepupae>cocoon. All samples have a deacetylation degree (DD) of more than 90 % except for chitosan from prepupae. FTIR profiles indicated all chitin extracted were in the α-form while the deacetylated chitosan matched closely to the commercially available chitosan. Overall, this study indicated that BSF biomass from different lifecycle phases could be a promising alternative resource for industrial chitin and chitosan production