Search

Improving the heat transfer performance of conventional fluid creates significant energy savings in process Industries. In this aspect, an experimental study was performed to evaluate the heat transfer performance of Fe2O3-water (W)-engine oil (EO) nanofluid at different concentrations and hot fluid inlet temperatures in a plate heat exchanger. Experiments were conducted by mixing Fe2O3 nanoparticles (45 nm) in a W-EO mixture base fluid with volume fractions of 5% EO + 95% W and 10% EO +90% W. The main aim of the present study was to assess the impacts of nanoparticle volume fraction and hot fluid inlet temperature variations on the heat transfer performance of the prepared nanofluid. The convective heat transfer coefficient, Reynolds, Prandtl, and Nusselt numbers were determined based on the experimental results. The result shows that at the hot fluid inlet temperature of 75 ?C, the increase in Nusselt number and convective heat transfer coefficient are optimum at 0.9 vol. % nanoparticle for both the base fluid mixtures. The increase in heat transfer coefficient is because of the Brownian motion (increasing thermal conductivity) effect, motion caused by the temperature gradient (Thermo-phoretic), and motion due to concentration gradient (Osmophoretic). If the volume fraction of the nanoparticle increases, then the Reynolds number increment is higher than the Prandtl number decrement, which augments the Nusselt number and convective heat transfer coefficient.

Augmentative and reconstructive rhinoplasty surgical procedures use autologous tissue grafts or synthetic grafts to repair the nasal defect and aesthetic reconstruction. Donor site trauma and morbidity are common in autologous grafts. The desperate need for the production of grafted 3D cartilage tissues as rhinoplasty grafts without the adverse effect is the need of the hour. In the present study, we developed a bioactive 3D histotypic construct engineered with the various ratio of adipose-derived stem cells (ADSC) and chondrocytes together with decellularized porcine nasal cartilage graft (dPNCG). We decellularized porcine nasal cartilage using supercritical carbon dioxide (SCCO2) extraction technology. dPNCG was characterized by H&E, DAPI, alcian blue staining, scanning electron microscopy and residual DNA content, which demonstrated complete decellularization. 3D histotypic constructs were engineered using dPNCG, rat ADSC and chondrocytes with different percentage of cells and cultured for 21 days. dPNCG together with 100% chondrocytes produced a solid mass of 3D histotypic cartilage with significant production of glycosaminoglycans. H&E and alcian blue staining showed an intact mass, with cartilage granules bound to one another by extracellular matrix and proteoglycan, to form a 3D structure. Besides, the expression of chondrogenic markers, type II collagen, aggrecan and SOX-9 were elevated indicating chondrocytes cultured on dPNCG substrate facilitates the synthesis of type II collagen along with extracellular matrix to produce 3D histotypic cartilage. To conclude, dPNCG is an excellent substrate scaffold that might offer a suitable environment for chondrocytes to produce 3D histotypic cartilage. This engineered 3D construct might serve as a promising future candidate for cartilage tissue engineering in rhinoplasty.

Thermal conductivity of a heat transfer fluid plays a significant role in improving the heat transfer performance of a heat exchanger. In this work, experiments were performed in a natural convection heat transfer apparatus by mixing homogenized Al2O3 nanoparticles in a base fluid of water-ethylene glycol mixtures. The effects of heat input, nanoparticle volume content in the base fluid, and ethylene-glycol volume content in the base fluid on thermal conductivity of the nanofluid were analyzed. Based on results obtained by MINITAB? design software (factorial design matrix), 16 experimental runs were performed with the lower and higher levels of input factors. The levels for heat input were 10 and 100 W; for nanoparticle volume content in the base fluid 0.1 and 1 vol.% and for the base fluid composition 30 and 50 vol.% of ethylene glycol in water. From the obtained experimental results, a Pareto chart, normal probability plot, contour plot and surface plot were drawn. Based on the results, a new correlation was proposed, and predictions were compared with the experimental results. From the study, the maximum thermal conductivity value 0.49 W m-1 K-1 was observed at a nanoparticle volume content in the base fluid of 1.0 vol.%, ethylene glycol volume content in the base fluid of 30 vol.% and heat input of 100 W.

Orbital floor fractures subsequently lead to consequences such as diplopia and enophthalmos. The graft materials used in orbital floor fractures varied from autografts to alloplastic grafts, which possess certain limitations. In the present study, a novel porcine bone matrix decellularized by supercritical CO2 (scCO2), ABCcolla® Collagen Bone Graft, was used for the reconstruction of the orbital framework. The study was approved by the institutional review board (IRB) of Kaohsiung Medical University Chung-Ho Memorial Hospital (KMUH). Ten cases underwent orbital floor reconstruction in KMUH in 2019. The orbital defects were fixed by the implantation of the ABCcolla® Collagen Bone Graft. Nine out of ten cases used 1 piece of customized ABCcolla® Collagen Bone Graft in each defect. The other case used 2 pieces of customized ABCcolla® Collagen Bone Graft in one defect area due to the curved outline of the defect. In the outpatient clinic, all 10 cases showed improvement of enophthalmos on CT (computerized tomography) at week 8 follow-up. No replacement of implants was needed during follow-ups. To conclude, ABCcolla® Collagen Bone Graft proved to be safe and effective in the reconstruction of the orbital floor with high accessibility, high stability, good biocompatibility, low infection rate and low complication rate.

The rise of tissue engineering and regenerative medicine (TERM) is a developing field that focuses on the advancement of alternative therapies for tissue and organ restoration. Collagen scaffold biomaterials play a vital role as a scaffold to promote cell growth and differentiation to promote the repair and regenerate the tissue lesion. The goal of this chapter will be to evaluate the role of supercritical carbon dioxide extraction technology in the production of collagen scaffold biomaterials from various tissues and organs and relate it to the traditional decellularization techniques in the production of collagen biomaterials for TERM. Therefore, we will study the collagen scaffold biomaterials produced using supercritical carbon dioxide extraction technology and their characteristics, such as chemical-physical properties, toxicity, biocompatibility, in vitro and in vivo bioactivity that could affect the interaction with cells and living system, relative to traditional decellularization technique-mediated collagen scaffolds. Furthermore, the chapter will focus on supercritical carbon dioxide extraction technology for the production of collagen scaffolds biomaterial appropriate for TERM.

Diabetes mellitus (DM) causes impaired wound healing by affecting one or more of the biological mechanisms of hemostasis, inflammation, proliferation, and remodeling and a large number of cell types, extracellular components, growth factors, and cytokines. Interventions targeted toward these mechanisms might accelerate the wound healing process. To evaluate the wound healing efficacy of supercritical carbon dioxide (scCO2)-decellularized porcine acellular dermal matrix (ADM) combined with autologous adipose-derived stem cells (ASCs) in streptozotocin (STZ)-induced DM rats. DM was induced by injecting rats with STZ; dorsal full-thickness skin (5 × 5 cm2) was created and treated with and without ASCs-scCO2-treated ADM to evaluate the wound healing rate through histological examination, fluorescence microscopic observation, and immunohistochemical analysis. In the present study, complete decellularization of the porcine dermal matrix was achieved through scCO2. Isolation of ASCs was conducted and evaluated using CD29+/CD31-/CD45-/CD90+ markers in flow cytometry, which indicated that more than 90% of cells were ASCs. The percentage of cells labeled with CD29+ and CD90+ was found to be 97.50% and 99.69%, respectively. The wound healing rate increased in all groups relative to the group with the DM wound without treatment. DM wound treated with ADM-ASCs showed significantly higher (p < 0.01) wound healing rate than DM wound without treatment. ADM-ASC-treated rats showed significantly increased epidermal growth factor, Ki67, and prolyl 4-hydroxylase and significantly decreased CD45 compared with the group with the DM wound without treatment. The intervention comprising ADM decellularized from porcine skin by using scCO2 and ASCs was proven to improve diabetic wound healing. ADM-ASCs had a positive effect on epidermal regeneration, anti-inflammation, collagen production and processing, and cell proliferation; thus, it accelerated wound healing.

Knee osteoarthritis (OA) is a common degenerative articular disorder and considered one of the primary causes of pain and functional disability. Knee OA is prevalent in 10% of men and 13% of women aged 60 years above. The study aims to use cartilage tissue engineering that combines the triads of decellularized porcine cartilage graft as "scaffold," plasma rich platelet (PRP) as "signal" and chondrocytes from rat as "cell" to attenuate ACLT-induced OA progression and regenerate the knee cartilage in rats. Decellularization of the porcine cartilage was characterized by hematoxylin and eosin, 4,6-Diamidino-2-phenylindole staining, scanning electron microscopy and residual DNA quantification. The protective effect of decellularized porcine cartilage graft (dPCG) was evaluated by intra-articular administration in surgically induced anterior cruciate ligament transection (ACLT) rat osteoarthritis (OA) model. Supercritical carbon dioxide technology completely decellularized the porcine cartilage. Intra-articular administration of dPCG with or without PRP significantly reduced the ACLT-induced OA symptoms and attenuated the OA progression. Pain-relief by dPCG with or without PRP was assessed by capacitance meter and improved articular cartilage damage in the rat knee was characterized by X-ray and micro-CT. Besides, the histological analysis depicted cartilage protection by dPCG with or without PRP. The repairation and attenuation effect by dPCG with or without PRP in the articular knee cartilage damage were also explored by safranin-O, type II collagen, aggrecan and SOX-9 immuno-staining. To conclude, intra-articular administration of dPCG with or without PRP is efficient in repairing the damaged cartilage in the experimental OA model.

PURPOSE The aim of this study was to develop a non-cytotoxic, biocompatible innovative acellular porcine cornea (APC) for corneal wound healing and corneal blindness treatment. METHODS APC was produced by using supercritical carbon dioxide (SCCO2) to decellularize the porcine cornea. Decellularization of the porcine cornea was examined by hematoxylin and eosin staining and 4,6-diamidino-2-phenylindole, dihydrochloride staining. The residual DNA content of APC was analyzed in comparison with the native porcine cornea. Virus inactivation up to at least 6 log10 was confirmed for the stepwise process of APC for 4 different model viruses. In addition, a series of in vitro and in vivo tests in accordance with ISO-10993 biocompatibility assay and animal performance tests were performed. RESULTS APC produced by the SCCO2 process revealed complete decellularization, without any residual non-collagenous proteins. The scanning electron microscopy structural features of the decellularized cornea were similar to those of human. APC was found to be nontoxic and exhibited excellent biocompatibility in both in vitro and in vivo studies. The animal performance test proved that APC exerted excellent adaptability on the cornea and no sign of irritation and good compatibility in lamellar corneal transplantation. CONCLUSIONS APC manufactured by SCCO2 technology revealed complete cells and non-collagenous protein removal compared with the Triton-sodium dodecyl sulfate decellularization process. APC showed excellent biocompatibility in rabbit lamellar corneal transplantation with a follow-up to 1 year. APC can be a potential substitute for human-donated cornea for corneal transplantation in the near future.

Extracellular matrix (ECM) scaffolds are extensively used in tissue engineering studies and numerous clinical applications for tissue and organ reconstructions. Due to the global severe shortage of human tissues and organs, xenogeneic biomaterials are a common source for human tissue engineering and regenerative medicine applications. Traditional methods for decellularization often disrupt the 3D architecture and damage the structural integrity of the ECM scaffold. To efficiently obtain natural ECM scaffolds from animal tissues and organs with intact architecture, we have developed a platform decellularization process using supercritical CO2 and tested its potential application in tissue engineering. A combination of human mesenchymal stem cells with a decellularized dermal matrix scaffold allowed complete regeneration of skin structure in a porcine full-thickness wound model.

Traditional purification of atelocollagen involves a harsh extraction process with environment-polluting chemicals and costly and/or time-consuming procedures which include salting-out, alkali, acid and enzymatic treatment and ion-exchange chromatography. The atelocollagen market is growing exponentially, with demand in the skincare industry and for various medical applications. As a result, there is an urgent need for an eco-friendly production process with minimal manipulation. We developed a novel technique involving supercritical carbon dioxide extraction technology to remove the cells and noncollagenous substances from the porcine hide. Subsequent processes allow the production of several products, including decellularized dermal membrane, high-purity collagen particles and atelocollagen. The advantages of our process are its faster speed and lower environmental impact and its generation of multiple products, including high purity atelocollagen with complete removal of telopeptides.

The current investigation was carried out to study the effect of gamma irradiations on decontamination of Withania somnifera and its antioxidant activity. W. somnifera dry roots were packed and irradiated at doses of 1–10 kGy following the storage at 4C within a week. At the dose of 10 kGy, the microbial contamination was lowered below detection level. Glycowithanolides are known for antioxidant components present in W. somnifera. The antioxidant activity of W. somnifera extract was investigated by measuring 1,1-diphenyl-2-picrylhydrazyl, hydroxyl and superoxide radical-scavenging activities. These activities were increased in samples extracted from the irradiated roots at 10 kGy. The extraction yield of the glycowithanolides was considered as one of the reasons for the increase of antioxidant activities of the extract. Practical Applications Withania somnifera is an important medicinal plant and has been widely used in India and other parts of the world as a home remedy for several diseases. Gamma irradiation has been used as a phytosanitary treatment of food and herbal materials. The present study was conducted to evaluate the effect of gamma irradiation on decontamination of W. somnifera and its effect on the antioxidant properties. These results suggest that gamma irradiation can be applied for phytosanitary of other herbal plants.

Acute pancreatitis is a potentially fatal disease with no known cure. The initial events in acute pancreatitis may occur within the acinar cells. We examined the effect of sesamol on (i) a cerulein-induced pancreatic acinar cancer cell line, AR42J, and (ii) cerulein-induced experimental acute pancreatitis in rats. Sesamol inhibited amylase activity and increased cell survival. It also inhibited medium lipid peroxidation and 8-hydroxydeoxyguanosine in AR42J cells compared with the cerulein-alone groups. In addition, in cerulein-treated rats, sesamol inhibited serum amylase and lipase levels, pancreatic edema, and lipid peroxidation, but it increased pancreatic glutathione and nitric oxide levels. Thus, we hypothesize that sesamol attenuates cerulein-induced experimental acute pancreatitis by inhibiting the pancreatic acinar cell death associated with oxidative stress in rats.

Gastric ulcers and related complications associated with the use of non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin, represent a major global health problem. In the present study, we investigate the immunological activity of fucoidan against aspirin-induced gastric mucosal damage in rats. Thirty-six rats were randomly divided into the following, normal (Carboxy methyl cellulose 0.05 %), aspirin (Asp-400mg/kg) treated, fucoidan alone (Fu-0.02 g/kg, daily for 14 days) and Fu+Asp. Cytokines, total nitrite and nitrate (NOx) analysis and tissue localization of Cyclooxygenase 1, 2 and epidermal growth factor receptor (EGFR) were done using Elisa and immunohistochemistry respectively. Histopathology of gastric tissue, collagen deposition was performed using Hematoxylin and Eosin and Masson's trichrome were performed. Treatment of rats with a single dose of aspirin (400mg/kg, orally) led to significant alterations in the levels of total nitrite and nitrate (NOx), interleukins (IL-4, 6, 10, 12), tumor necrosis factor (TNF-α), and interferon gamma (IFN-γ). Notably, collagen deposition in glandular tissue and localization of cyclooxygenase 1, 2, and epidermal growth factor were considerably affected in aspirin-treated rats. These severities were prevented to a significant extent in rats pretreated with fucoidan (0.02 g/kg/day for two weeks orally). Our findings collectively indicate that the gastro-protective effect of fucoidan against aspirin-induced ulceration in rats is mediated through its immunomodulatory properties.

The objective of this study was to evaluate the effect of ionizing radiation on color and antioxidative properties of Chaga mushroom (Inonotus obliquus) extract (CME). CME (10 mg/mL) was gamma-irradiated at 0, 3, 5, 7, and 10 kGy, and color, antioxidant activity, and total phenolic compound levels were then determined. The lightness and yellowness were increased (P < .05), and the redness was decreased (P < .05), as irradiation dose increased. The antioxidant parameters such as the 2-diphenyl-1-picrylhydrazyl, superoxide, and hydroxyl radical scavenging activities, ferric reducing/antioxidant power, and inhibition of lipid peroxidation increased as the irradiation dose increased. Also, the total phenolic compound levels of CME were increased (P < .05) by gamma-irradiation. These results suggest that gamma-irradiation could be considered a means for improving the antioxidant properties and the color of CME.

Tamarind (Tamarindus indica L) seed polysaccharide (TSP) is of great important due to its various biological activities. The present investigation was carried out to compare extraction yield, morphological characteristics, average molecular weights and antioxidant activities of TSP from gamma- and electron beam (EB)-irradiated tamarind kernel powder. The tamarind kernel powder was irradiated with 0, 5 and 10 kGy by gamma ray (GR) and electron beam, respectively. The extraction yield of TSP was increased significantly by EB and GR irradiation, but there was no significant difference between irradiation types. Morphological studies by scanning electron microscope showed that TSP from GR-irradiated tamarind seed had a fibrous structure, different from that of EB irradiated with a particle structures. The average molecular weight of TSP was decreased by the irradiation, and EB treatment degraded more severely than GR. Superoxide radical scavenging ability and total antioxidant capacity of EB-treated TSP showed higher than those of GR-treated TSP.

Antioxidants quench oxidation by transferring hydrogen atoms to free radicals. In the present investigation, the effect of gamma irradiation on the natural antioxidants of irradiated cumin was studied. Cumin samples were purchased from retailers and then irradiated in a cobalt-60 irradiator to 0, 1, 3, 5 and 10 kGy at ambient temperature. The effect of irradiation on the antioxidant properties of the cumin seed were investigated by evaluating the radical-scavenging effect on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, determination of ferric reducing antioxidant power (FRAP), total polyphenol content (TPC) and the antioxidant index by β-carotene/linoleic acid co-oxidation. Electron spin resonance (ESR) was performed to assess ionization of cumin seeds by gamma irradiation. Irradiation was found to nonsignificantly increase and/or maintain all antioxidant parameters, TPC and the ESR signal intensity was found to be increased in cumin seeds.

Gamma irradiation is highly effective in inactivating microorganisms in various foods and it offers a safe alternative method of food decontamination. In the present study, the effect of gamma irradiation on microbial analysis, antioxidant activity, sugar content, color and sensory evaluation of ready-to-use tamarind juice was investigated during storage. A fresh tamarind juice was prepared by dissolving 5 g of pulp/100 ml of deionized distilled water and irradiated at 0, 1, 3 and 5 kGy at room temperature. Microbiological assay of the fresh and stored ready-to-use tamarind juice showed better quality after gamma irradiation. Antioxidant ability was studied by using 1,1-diphenyl-2-picrylhydrazyl (DPPH), FRAP (ferric reducing/antioxidant power) and total phenolic contents, and gamma irradiation had a significant increase or maintenance on the antioxidant potential of the ready-to-use tamarind juice. Contents of glucose and fructose also showed minimal alterations both in the fresh and stored samples. There was a significant improvement in the Hunter color value in both the fresh and stored tamarind juice. To conclude, gamma irradiation improves the microbial decontamination and the antioxidants as well as the color of the ready-to-use tamarind juice without any adverse change in sensory qualities.