Three-Dimensional Printed Cellulose for Wound Dressing Applications.

Wounds are skin tissue damage due to trauma. Many factors inhibit the wound healing phase (hemostasis, inflammation, proliferation, and alteration), such as oxygenation, contamination/infection, age, effects of injury, sex hormones, stress, diabetes, obesity, drugs, alcoholism, smoking, nutrition, hemostasis, debridement, and closing time. Cellulose is the most abundant biopolymer in nature which is promising as the main matrix of wound dressings because of its good structure and mechanical stability, moisturizes the area around the wound, absorbs excess exudate, can form elastic gels with the characteristics of bio-responsiveness, biocompatibility, low toxicity, biodegradability, and structural similarity with the extracellular matrix (ECM). The addition of active ingredients as a model drug helps accelerate wound healing through antimicrobial and antioxidant mechanisms. Three-dimensional (3D) bioprinting technology can print cellulose as a bioink to produce wound dressings with complex structures mimicking ECM. The 3D printed cellulose-based wound dressings are a promising application in modern wound care. This article reviews the use of 3D printed cellulose as an ideal wound dressing and their properties, including mechanical properties, permeability aspect, absorption ability, ability to retain and provide moisture, biodegradation, antimicrobial property, and biocompatibility. The applications of 3D printed cellulose in the management of chronic wounds, burns, and painful wounds are also discussed.

High yield production of nanocrystalline cellulose from corn cob through a chemical-mechanical treatment under mild conditions.

Agricultural biomass waste such as corn cob is available in large quantities and can be used as renewable materials for various applications. Corn cob was converted into nanocrystalline cellulose by using mild sulfuric acid concentrations (30 % w/v) at low temperature (50 °C) and a relatively shorter time extraction (30 min) combined with mechanical treatment using a conventional high-speed blender. NCC from cellulose and α-cellulose from corn cobs have been successfully isolated with relatively high yields and crystallinities of 50.07-65.33 % and 65.5-69.9 %, respectively. Scanning electron microscopy (SEM) evaluated the morphological variation and dimension from corn cob fiber (CF), delignification fiber (DF), cellulose, and α-cellulose, which shows that each pretreatment stage causes a decrease in fiber diameter from 16.56 to 5.48 µm. Transmission electron microscopy (TEM) images confirmed the nano-scale dimension with fiber diameters ranging between 9.35 nm and 6.51 nm. Thermogravimetric analysis shows that NCC has relatively high thermal stability ranging from 429 to 437 °C. Thus, this characteristic of NCC has the potential to be applied as a reinforcing agent in various fields of polymer composites. Finally, this study presents a method for isolating NCC from corncob waste using a conventional high-speed blender in a mild condition process with a relatively low cost, environmentally friendly pathway, and high yield that was still preserved.