In this work, a new method for producing acellular dermis (ADM), a natural scaffold used for dermal replacement, from porcine skin was developed. Fresh porcine skin from local slaughterhouse was dehaired by sodium sulphide following by epidermis removal using glycerol. After fat removal by chloroform/methanol (2/1 v/v) solvent, cellular components were removed using enzymatic treatment incorporated with a periodic pressurized technique. The effects of enzyme type (trypsin and dispase II) and periodic pressurized conditions on the efficiency of cell removal were investigated. When periodic pressure was applied, enzymatic treatment time could be shorten since the enzyme solution was able to penetrate into tight dermis. As a result, cells could be easily removed from porcine skin as noticed quantitatively by DNA assay and qualitatively by H&E staining. When enzyme refreshment was introduced into the decellularized process, the percentage of cell removal was further enhanced. This ensured that no inhibitions effect from the removed cells on enzyme-substrate interaction. Moreover, short-time enzymatic treatment with periodic pressurized technique could prevent the disruption of dermal structure, as observed by SEM. Dispase II can be used to remove cell better than trypsin in the periodic pressurized technique. However, in vivo study indicated that numerous fibroblast from the host tissue infiltrated into ADM prepared using both enzymes. Neo-collagen and neo-capillaries were produced in both implanted ADMs. The result elucidated that the use of periodic pressurized technique with enzymatic treatment has a high potential to be a new method to produce ADM for skin tissue engineering.

This research evaluated the feasibility of using vetiver plantlets (Vetiveria zizanioides (L.) Nash) on a floating platform with aeration to degrade phenol (500 mg/L) in illegally dumped industrial wastewater (IDIWW). The IDIWW sample was from the most infamous illegal dumping site at Nong Nae subdistrict, Phanom Sarakham district, Chachoengsao province, Thailand. Laboratory results suggested that phenol degradation by vetiver involves two phases: Phase I, phytopolymerization and phyto-oxidation assisted by root-produced peroxide (HO) and peroxidase (POD), followed by phase II, a combination of phase I with enhanced rhizomicrobial degradation. The first 360-400 h of phenol degradation were dominated by phytopolymerization and phyto-oxidation yielding particulate polyphenols (PPP) or particulate organic matter (POM) as by-products, while phenol decreased to around 145 mg/L. In Phase II, synergistically, rhizomicrobial growth was ∼100-folds greater on the roots of the vetiver plantlets than in the IDIWW and participated in the microbial degradation of phenol at this lower phenol concentration, increasing the phenol degradation rate by more than three folds. This combination of phytochemical and rhizomicrobiological processes eliminated phenol in IDIWW in less than 766 h (32 days), while without the vetiver plantlets, phenol degradation by aerated microbial degradation alone may require 235 days. To our knowledge, this is the first that systematically reveals the complete phenol degradation mechanism by vetiver plantlets in real aerated wastewater.

This study uses discharges in solutions for the treatment of gelatin solutions in order to generate crosslinking. The effects of plasma on the properties of gelatin solutions were investigated, the latter including viscosity, amino acid contents, chemical analyses, and gel strengths. The results show that, after short duration plasma treatments (5–10 min), the viscosity of the gelatin solutions increased, while the concentration of OH· free radicals decreased. After adding ethanol to the gelatin solutions, a greater increase in viscosity, and a greater decrease in free radicals were found. This suggests that ethanol provides more free radicals that can promote the crosslinking of the gelatin solution during the plasma treatment, resulting in higher viscosity. The gel strength of the gelatin was greatly enhanced by the plasma treatment of the solution. The results regarding the free amino acid contents showed that the crosslinking degree of plasma‐treated gelatin was higher than that of the untreated gelatin. FTIR measurements show that after plasma treatment, the IR bands at 1 668 and 1 558 cm−1, corresponding to the amide I and II groups of gelatin, shifted to higher wavenumbers, i.e. 1 672 and 1 564 cm−1, respectively. This suggests that crosslinking has occurred between gelatin molecules. The results show that discharges in solutions may be able to induce crosslinking reactions in the gelatin. Electrical discharges in solutions can be chemical‐free, alternative crosslinking methods.

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