Cheng-Kang Lee

Nowadays, an efficient and environmentally friendly polyethylene terephthalate (PET) recycling method has gained greater attention, enabling a circular economy for polyesters. Since PET is a hydrophobic polymer, the enzyme's binding affinity to PET becomes a significant issue. Herein, the first strategy is introduced to enhance PET fiber hydrolysis by genetically fusing hydrolyzing enzymes such as cutinase and PETase to protein hydrophobin HGFI. HGFI, a surface-active protein from Grifola frondosa, was used to improve the rate of enzyme hydrolysis. Furthermore, cellulose binding domains (CBD) were employed as a solubility enhancer tag of PETase fusion due to the insoluble characteristics of HGFI and PETase. The fusion proteins (CBD-HGFI-PETase and HGFI-Cut_2) were constructed with a flexible linker, expressed in Escherichia coli, and then purified by chromatography. PETase fusion exhibited 2.5-fold higher concentrations of monomer products released than that of cutinase fusion after 5 days of hydrolysis. According to the results, the fusion of HGFI to PETase showed excellent performance for enhancing the binding affinity of the enzyme on PET fiber substrate due to the increasing number of self-assembled hydrophobin interactions that modified the PET surface to be more hydrophilic. Therefore, this study indicates that the construction of CBD-HGFI-PETase enzyme fusion could be used as a novel method for efficiently accelerating PET biodegradation.

Mature lysostaphin (mLst) is a glycineglycine endopeptidase, capable of specifically cleaving penta-glycine crosslinker in the peptidoglycan of Staphylococ

Polyvinyl alcohol (PVA) nanofibrous membrane, consisting of separately encapsulated glucose oxidase (GOx) and glucose (Glu) nanofibers, was prepared via simultaneously electrospinning PVA/GOx and PVA/Glu dopes. The as-prepared pristine membrane could self-sustainably generate hydrogen peroxide (H₂O₂) only in contact with an aqueous solution. The H₂O₂ production level was well maintained even after storing the dry membrane at room temperature for 7 days. Cross-linking the membrane via reaction with glutaraldehyde (GA) vapor could not only prevent the nanofibrous membrane from dissolving in water but also prolonged the release of H₂O₂. The sustained release of H₂O₂ from the membrane achieved antimicrobial capability equivalent to that of 1% H₂O₂ against both Escherichia coli and Staphylococcus aureus. Gram(+) S. aureus cells were more susceptible to H₂O₂ than Gram(−) E. coli and >99% of S. aureus were killed after 1 h incubation with the membrane. Pristine and GA-crosslinked nanofibrous membrane with in situ production of H₂O₂ were self-sterilized in which no microorganism contamination on the membrane could be detected after 2 weeks incubation on an agar plate. The GOx/Glu membrane may find potential application as versatile antimicrobial materials in the field of biomedicine, in the food and health industries, and especially challenges related to wound healing in diabetic patients.

Hyaluronic acid (HA) is conjugated with BHQ3 moiety with azo bonds to prepare hypoxia-responsive polymer conjugate. Because of the amphiphilic nature, the polymer conjugate self-assembles to HA-BHQ3 nanoparticles (NPs). The anticancer drug doxorubicin (DOX) is loaded into the NPs. In the physiological environment, DOX is released slowly. In contrast, under hypoxic conditions, the azo bond in BHQ3 is cleaved, thus significantly enhancing the DOX release rate. For instance, after 24 h, 25% of DOX is released under normal conditions, while 74% of DOX is released under hypoxic conditions. In vitro cytotoxicity demonstrates higher toxicity in the hypoxic conditions. [email protected] NPs exhibit greater toxicity levels against 4T1 cells in hypoxic conditions. The fluorescent microscope images confirm the oxygen-dependent intracellular DOX release from the NPs. The in vivo biodistribution results suggest the tumor targetability of HA-BHQ3 NPs in 4T1 tumor-bearing mice.

The development of reliable and robust diagnostic tests is one of the most efficient methods to limit the spread of coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). However, most laboratory diagnostics for COVID-19, such as enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR), are expensive, time-consuming, and require highly trained professional operators. On the other hand, the lateral flow immunoassay (LFIA) is a simpler, cheaper device that can be operated by unskilled personnel easily. Unfortunately, the current technique has some limitations, mainly inaccuracy in detection. This review article aims to highlight recent advances in novel lateral flow technologies for detecting SARS-CoV-2 as well as innovative approaches to achieve highly sensitive and specific point-of-care testing. Lastly, we discuss future perspectives on how smartphones and Artificial Intelligence (AI) can be integrated to revolutionize disease detection as well as disease control and surveillance.

A norbornene-derived hydrazone polymer was developed for high selectivity, and to be used as an effective colorimetric and fluorescent chemosensor of Al ³⁺ in aqueous solutions.

Polyethylene terephthalate (PET) becomes one of the most well-known polyesters and is widely used as packaging material. Recently, polyethylene terephthalate hydrolase (PETase) has emerged as a potential biocatalyst demonstrating the ability to degrade polyethylene terephthalate (PET). We showed that the rate of PETase hydrolysis could be significantly increased in the presence of hydrophobin RolA. Hydrophobins represent a class of small fungal protein that has a high surface-active substance and can spontaneously self-assemble at hydrophilic-hydrophobic interfaces. In this work, a class I hydrophobin named RolA was extracted from the mycelium pellet collected from a fermentation culture of Aspergillus oryzae. The SDS-PAGE analysis of the isolated RolA showed the presence of 11 kDa polypeptide. Recombinant PETase from Ideonella sakaiensis was also successfully expressed in Escherichia coli as a soluble protein with molecular weight approximately 30 kDa. The hydrophobin RolA could enhance the PET hydrolysis in the presence of the recombinant PETase. The hydrolysis of PET bottle by RolA-PETase achieved the highest weight loss of 26% in 4 days. It is speculated that the wetting effect of RolA acts on PET surface converts PET to become hydrophilic that leads PETase easier to contact and attack the surface. Graphical Abstract