Enzyme immobilization has been known to be one of the methods to improve the stability and reusability of enzyme. In this study, a strategy to optimize laccase immobilization on polyethylene terephthalate grafted with maleic anhydride electrospun nanofiber mat (PET-g-MAH ENM) was developed. The development involves the screening and optimization processes of the crucial factors that influence the immobilization yield such as enzyme concentration, pH values, covalent bonding (CV) time, CV temperature, crosslinking (CL) time, CL temperature and glutaraldehyde concentration using two-level factorial design and Box-Behnken design (BBD), respectively. It was found that laccase concentration, pH values and glutaraldehyde concentration play important role in enhancing the immobilization yield of laccase on PET-g-MAH ENM in the screening process. Subsequently, the optimization result showed at 0.28 mg/ml laccase concentration, pH 3 and 0.45% (v/v) glutaraldehyde concentrations gave the highest immobilization yield at 87.64% which was 81.2% increment from the immobilization yield before optimization. Under the optimum condition, the immobilized laccase was able to oxidize 2, 2-azino-bis 3-ethylbenzothiazoline-6- sulfonic acid (ABTS) in a broad range of pH (pH 3-6) and temperature (20- 70 °C). Meanwhile, the kinetic parameters for Km and Vmax were 1.331 mM and 0.041 mM/min, respectively. It was concluded that the optimization of immobilized laccase on PET-g-MAH ENM enhance the performance of this biocatalyst.
Food-drug interphase products, referring to nutraceuticals in this study, are a category of health products containing a combination of food ingredients with active substances for oral consumption. Many of these products are marketed as an alternative to prescription medicine to treat various ailments despite the lack of scientific evidence, influencing patients with chronic diseases to consume nutraceutical products. This study aimed to determine the prevalence and factors associated with knowledge, attitude, and practice of nutraceutical use among patients with chronic disease attending to the outpatient clinic. This is a cross-sectional study involving patients with chronic disease at the outpatient specialist clinic. Samples were recruited from the outpatient clinic using convenience sampling. Data was collected using a self-administered questionnaire, which was self-constructed and validated. We found that the use of nutraceuticals was prevalent among 17.9% of respondents. More than half (60.9%) of the respondents have poor knowledge of nutraceutical and 53.1% of respondents have a positive attitude towards nutraceutical. Gender and morbidities were the factors associated with the practice of nutraceutical usage. Female patients are more likely to have increased use of nutraceutical than male patients and patients with multiple morbidities have higher odds of using nutraceutical than patients with single morbidities. There is a high number of patients who consume nutraceutical products and public knowledge of nutraceutical needs to be improved further. The government should develop appropriate regulation and monitoring of nutraceutical products.