Surface Roughness, Dynamic Wettability, and Interphase of Modified Melamine Formaldehyde-Based Adhesives on Jabon Wood

The surface roughness and wettability of wood are critical aspects to consider when producing laminated wood products with adhesive applications. This study aims to investigate the surface roughness and dynamic wettability of Jabon wood in the presence of melamine formaldehyde (MF)-based adhesives. Commercial MF adhesives (MF-0) and modified MF adhesives (MF-1) were applied to Jabon wood, which includes tangential (T), radial (R), and semi-radial (T/R) surfaces. The surface roughness of Jabon wood was assessed using a portable stylus-type profilometer. The low-bond axisymmetric drop shape analysis (LB-ADSA) method was employed to identify the contact angle (θ) of the MF-based adhesives on Jabon wood. The wettability was determined by evaluating the constant contact angle change rate (K value) using the Shi and Gardner (S/G) model. Dynamic mechanical analysis (DMA) was employed to investigate the viscoelastic characteristics of the interphase analysis of the wood and MF-based adhesives. The roughness level (Ra) of the Jabon board ranged from 5.62 to 6.94 µm, with the T/R having a higher level of roughness than the R and T. MF-0 exhibited a higher K value (0.262-0.331) than MF-1 (0.136-0.212), indicating that MF-0 wets the surface of Jabon wood more easily than MF-1. The wood-MF-0 interphase reached a maximum stiffness of 957 N/m at 123.0 °C, while the wood-MF-1 had a maximum stiffness of 2734 N/m at 110.5 °C. In addition, the wood-MF-0 had a maximum storage modulus of 12,650 MPa at a temperature of 128.9 °C, while the wood-MF-1 had a maximum storage modulus of 22,950 MPa at 113.5 °C.

Breadmaking-Inspired Antioxidant Porous Yeast Microcarriers for Stem Cell Delivery in Diabetic Wound Treatment

Stem cell-based therapies have exhibited significant promise in the treatment of diabetic ulcers (DU). Nevertheless, enhancing the survival rate and functionality of transplanted stem cells poses a substantial challenge. In this study, inspired by the breadmaking process, yeast microcarriers (YMC) are devised as vehicles for stem cells to address these challenges. The fabrication of YMC involves the amalgamation of microfluidic emulsification with yeast-mediated fermentation, yielding microcarriers with outstanding biocompatibility, high porosity, and antioxidant activity. Adipose-derived stem cells (ADSCs) seeded onto YMC display remarkable cell viability and retain their cellular functions effectively. Additionally, YMC boast a rich glutathione content and exhibit remarkable ROS scavenging ability, thus shielding the ADSCs from oxidative stress. In vivo experiments further substantiate that ADSC@YMC implementation significantly lowered ROS levels in diabetic wounds, resulting in enhanced stem cell retention and improved angiogenesis, collagen deposition, and tissue regeneration. These results highlight the potential of ADSC@YMC as a promising platform for delivering stem cell in the treatment of diabetic wounds.

Electrospun Magnetic Nanofiber Mats for Magnetic Hyperthermia in Cancer Treatment Applications-Technology, Mechanism, and Materials

The number of cancer patients is rapidly increasing worldwide. Among the leading causes of human death, cancer can be regarded as one of the major threats to humans. Although many new cancer treatment procedures such as chemotherapy, radiotherapy, and surgical methods are nowadays being developed and used for testing purposes, results show limited efficiency and high toxicity, even if they have the potential to damage cancer cells in the process. In contrast, magnetic hyperthermia is a field that originated from the use of magnetic nanomaterials, which, due to their magnetic properties and other characteristics, are used in many clinical trials as one of the solutions for cancer treatment. Magnetic nanomaterials can increase the temperature of nanoparticles located in tumor tissue by applying an alternating magnetic field. A very simple, inexpensive, and environmentally friendly method is the fabrication of various types of functional nanostructures by adding magnetic additives to the spinning solution in the electrospinning process, which can overcome the limitations of this challenging treatment process. Here, we review recently developed electrospun magnetic nanofiber mats and magnetic nanomaterials that support magnetic hyperthermia therapy, targeted drug delivery, diagnostic and therapeutic tools, and techniques for cancer treatment.

Yeast fermentation inspired Ca-alginate hydrogel membrane: lower transparency, hierarchical pore structure and higher hydrophobicity

With a fantastic combination of yeast fermentation and hydrogel membrane formation, a series of microorganism inspired porous hydrogel membranes (MIHM) with various mass ratios of yeast/sodium alginate (SA) were developed. The yeast cells were firstly activated by addition of glucose for generating byproduct carbon dioxide (CO₂), inducing the formation of porous structures. The ionic cross-linking between calcium chloride and SA was subsequently performed based on an egg-box model. It is of interest to note that the obtained MIHM hydrogel membranes exhibited decreased transparency and hierarchical porous structure with pore sizes varying from 2 nm to 1 mm, giving rise to significantly increased contact angle (CA) values from 63.65° to 107.83° and obviously decreased equilibrium swelling ratios from 79.72 to 18.05. Especially, the adsorption kinetics of crystal violet (CV) show that the MIHM hydrogel membrane exhibited an encouraging uptake capacity of 18.40 mg g⁻¹ at 10 mg g⁻¹ and the adsorption kinetics of CV could be well defined by a pseudo-first-order kinetic equation. Owing to great advantages in facile fabrication, high efficiency, low cost and desirable biocompatibility, the MIHM hydrogel membrane can be large-scale fabricated and used for industry and agriculture.

CO₂ from yeast fermentation was used to prepare a porous hydrogel membrane with decreased transparency, hierarchical pores and increased hydrophobicity.

Analysis of extracellular vesicles produced in the biofilm by the dimorphic yeast Pichia fermentans

The yeast Pichia fermentans DISAABA 726 strain (P. fermentans) is a dimorphic yeast that under different environmental conditions may switch from a yeast-like to pseudohyphal morphology. We hypothesize that exosomes-like vesicles (EV) could mediate this rapid modification. EV are membrane-derived vesicles carrying lipids, proteins, mRNAs and microRNAs and have been recognized as important mediators of intercellular communication. Although it has been assumed for a long time that fungi release EV, knowledge of their functions is still limited. In this work we analyze P. fermentans EV production during growth in two different media containing urea (YCU) or methionine (YCM) where yeast-like or pseudohyphal morphology are produced. We developed a procedure to extract EV from the neighboring biofilm which is faster and more efficient as compared to the widely used ultracentrifugation method. Differences in morphology and RNA content of EV suggest that they might have an active role during dimorphic transition as response to the growth conditions. Our findings are coherent with a general state of hypoxic stress of the pseudohyphal cells.

Multifunctional Stiff Carbon Foam Derived from Bread

The creation of stiff yet multifunctional three-dimensional porous carbon architecture at very low cost is still challenging. In this work, lightweight and stiff carbon foam (CF) with adjustable pore structure was prepared by using flour as the basic element via a simple fermentation and carbonization process. The compressive strength of CF exhibits a high value of 3.6 MPa whereas its density is 0.29 g/cm(3) (compressive modulus can be 121 MPa). The electromagnetic interference (EMI) shielding effectiveness measurements (specific EMI shielding effectiveness can be 78.18 dB·cm(3)·g(-1)) indicate that CF can be used as lightweight, effective shielding material. Unlike ordinary foam structure materials, the low thermal conductivity (lowest is 0.06 W/m·K) with high resistance to fire makes CF a good candidate for commercial thermal insulation material. These results demonstrate a promising method to fabricate an economical, robust carbon material for applications in industry as well as topics regarding environmental protection and improvement of energy efficiency.