natural polymer-based bilayer adhesive skin substitute for infected burned wound healing

Thermal wounds are complex and lethal with irregular shapes, risk of infection, slow healing, and large surface area. The mortality rate in patients with infected burns is twice that of non-infected burns. Developing multifunctional skin substitutes to augment the healing rate of infected burns is vital. Herein, we 3D printed a hydrogel scaffold comprising carboxymethyl chitosan (CMCs) and oxidized alginate grafted catechol (O-AlgCat) on a hydrophobic electrospun layer, forming a bilayer skin substitute (BSS). The functional layer (FL) was fabricated by physiochemical crosslinking to ensure favorable biodegradability. The gallium-containing hydrophobic electrospun layer or backing layer (BL) could mimic the epidermis of skin, avoiding fluid penetration and offering antibacterial activity. 3D printed FL contains catechol, gallium, and biologically active platelet rich fibrin (PRF) to adhere to both tissue and BL, show antibacterial activity, encourage angiogenesis, cell growth, and migration. The fabricated bioactive BSS exhibited noticeable adhesive properties (P ≤ 0.05), significant antibacterial activity (P ≤ 0.05), faster clot formation, and the potential to promote proliferation (P ≤ 0.05) and migration (P ≤ 0.05) of L929 cells. Furthermore, the angiogenesis was significantly higher (P ≤ 0.05) when evaluated in vivo and in ovo. The BSS-covered wounds healed faster due to low inflammation and high collagen density. Based on the obtained results, the fabricated bioactive BSS could be an effective treatment for infected burn wounds.

Assessment of biosafety implementation in clinical diagnostic laboratories in Pakistan during the COVID-19 pandemic

Laboratory diagnostic capacity is crucial for an optimal national response to a public health emergency such as the COVID-19 pandemic.Preventing laboratory-acquired infections and the loss of critical human resources,especially during a public health emergency,requires laboratories to have a good biorisk management system in place.In this study,we aimed to evaluate laboratory biosafety and biosecurity in Pakistan during the COVID-19 pandemic.In this cross-sectional study,a self-rated anonymous questionnaire was distributed to laboratory professionals(LPs)working in clinical diagnostic laboratories,including laboratories performing polymerase chain reaction(PCR)-based COVID-19 diagnostic testing in Punjab,Sindh,Khyber Pakhtunkhwa,and Gilgit-Baltistan provinces as well as Islamabad during March 2020 to April 2020.The questionnaire assessed knowledge and perceptions of LPs,resource availability,and commitment by top management in these laboratories.In total,58.6%of LPs performing COVID-19 testing reported that their laboratory did not conduct a biorisk assessment before starting COVID-19 testing in their facility.Only 31%of LPs were aware that COVID-19 testing could be performed at a biosafety level 2 laboratory,as per the World Health Organization interim biosafety guidelines.A sufficiently high percentage of LPs did not feel confident in their ability to handle COVID-19 samples(32.8%),spills(43.1%),or other accidents(32.8%).These findings demonstrate the need for effective biosafety program implementation,proper training,and establishing competency assessment methods.These findings also suggested that identifying and addressing gaps in existing biorisk management systems through sustainable interventions and preparing LPs for surge capacity is crucial to better address public health emergencies.