Electrospinning of Polycaprolactone (PCL) and Gelatin Polymeric Fibers

Electrospinning is one of the commonly used polymeric fiber production technique, owing to its versatility and flexibility in spinning a wide range of polymers for various applications including tissue engineering. However, recent researches have been extensively focusing on exploring the electrospinnability of different polymers without fully realizing how the electrospinning parameters influence the electrospun fibrous structure, as the microstructure morphology will significantly affect the performance of electrospun membranes. The present work demonstrates the robustness of electrospinning technique in producing electrospun fibrous membranes with different microstructure morphology by altering the electrospinning parameters. Both PCL and gelatin solutions have been successfully transformed into electrospun fibrous membranes using an electrospinning machine. The PCL fibrous membranes consisted of beads and non-homogenous fibers while the gelatin membranes showed homogenous size of electrospun fibers. Results also revealed that the electrospinning parameters including solution and process parameters determined the microstructure morphology of electrospun membrane. The spindle-like beads in PCL membrane transformed into spherical size at higher solution concentration and applied voltage. Meanwhile, the gelatin membrane demonstrated similar morphology at different tip-collector distance. The size of gelatin fibers was also similar. Through this work, basic understanding on how the electrospinning parameters affect the morphology of different types of polymeric fibrous membrane can provide an insight for other researchers in facilitate production of electrospun membranes with desired microstructure morphology

Alterations in SAMD9, AHSG, FRG2C, and FGFR4 Genes in a Case of Late-Onset Massive Tumoral Calcinosis

Background/Objective: Tumoral calcinosis (TC) is a rare, arcane, and debilitating disorder of phosphate metabolism manifesting as hard masses in soft tissues. Primary hyperphosphatemic TC has been shown to be caused by pathogenic variants in the genes encoding FGF23, GALNT3, and KLOTHO. We report a case of massive TC mechanistically associated with phosphatonin resistance associated with heterozygous alterations in the sterile alfa motif domain–containing protein-9 gene (SAMD9), alfa 2-Heremans-Schmid glycoprotein gene (AHSG), FSHD region gene 2-family member-C gene (FRG2C), and fibroblast growth factor receptor-4 gene (FGFR4). Case Report: A middle-aged Malay woman with systemic sclerosis presented with painful hard lumps of her axillae, lower limbs, and external genitalia. She was eucalcemic with mild hyperphosphatemia associated with reduced urinary phosphate excretion. Magnetic resonance imaging revealed calcified soft tissue masses. Paradoxically, the serum intact FGF23 level increased to 89.6 pg/mL, corroborated by Western blots, which also showed overexpression of sFRP4 and MEPE, consistent with phosphatonin resistance. Discussion: Whole genome sequencing identified 2 heterozygous alterations (p.A454T and p.T479M) in SAMD9, 2 heterozygous alterations (p.M248T and p.S256T) in AHSG, a frameshift alteration (p.Arg156fs) in FRG2C, and a heterozygous alteration (p.G388R) in FGFR4, all of which are associated with calcinosis. Nonsynonymous alterations of FRP4 and MEPE were also detected. Conclusion: This highlights that the simultaneous occurrence of alterations in several genes critical in phosphate homeostasis may trigger massive TC despite their heterozygosity. These findings should prompt functional studies in cell and animal models to reveal mechanistic insights in the pathogenesis of such crippling mineralization disorders

Strategy on the production of bead free electrospun gelatin scaffolds

Electrospun scaffolds consist of micro-scale or nano-scale porous fibrous networks. These electrospun scaffolds had become increasingly popular in tissue engineering filed as it could provide nano-environment for cell culture and produced by using biodegrable polymer. One of the important key to provide such environment for cell culture is the porosity of the electrospun scaffolds as it is highly related with the cell-cell interaction. The porosity of the electrospun scaffolds could be affected by bead formation which is one of the common problems faced in electrospinning process. However, the formation of beads are difficult to be controlled as it depends on environmental factors such as humidity and operating temperature. Controlling these two environmental factors normally requires an expensive control system. This paper aims to solve the problem of bead formation by adjusting material concentration and process parameters without controlling the environmental factors. The parameters studied in this paper include polymer concentration, flow rate, distance between the syringe needle tip and collector and applied voltage. The microstructure of the electrospun scaffolds produced were visualised using scanning electron microscopy (SEM) and were analysed in terms of bead formation and fiber diameter. This study shows that polymer concentration is the best strategy to prevent bead formation in gelatin scaffolds while other process parameters such as applied voltage, distance between the syringe needle tip and the collector as well as flow rate can be used to control the fiber diameter. An understanding of the effects of each parameter provides a guideline to control microstructure morphology by producing bead-free electrospun gelatin scaffolds

Synthetic and Natural Fibrous Scaffolds for Soft Tissue Engineering Applications / Weily Khoo ...[et al.]

Fibrous scaffolds have been extensively studied as grafts for damaged tissue, owing to their physical architecture mimicking the native tissues like articular cartilage and skin. Developing mechanical robust fibrous scaffolds is therefore a critical issue to prevent scaffold failure that limits their applications in tissue engineering. This paper demonstrates our latest development of synthetic and natural fibrous scaffolds having physical architectures and mechanical properties comparable to that of native biological soft tissues. Synthetic fibrous scaffold was produced from gelatin solution using electrospinning technique while natural fibrous scaffold was extracted from small intestinal submucosa (SIS) of cattle. The SIS membrane was first decellurized and further reinforced with alginate hydrogel to form 3D composite scaffold. The physical architectures of both synthetic and natural fibrous scaffolds including thickness and microstructure morphology were characterized. SIS fibrous membrane reinforced with alginate hydrogel demonstrated more than 10 times of increment in scaffold thickness. Through scanning electron microscope (SEM) visualization, the synthetic fibrous scaffold demonstrated microstructures that mimic nanometer fiber and porous structure of soft collagenous tissues. Uniaxial tensile and fracture tests were performed to determine the tensile properties and fracture toughness of fibrous scaffolds. Both types of scaffolds showed tensile strength (0.81 – 38.30 MPa) and fracture toughness (0.86 – 32.52 kJ/m2) comparable to natural soft collagenous tissues. The developed tissue engineered scaffolds not only exhibit physical architectures mimicking native tissue structures but also demonstrate mechanical properties comparable to the native soft tissues

Electrospinning of Polycaprolactone (PCL) and Gelatin Polymeric Fibers / Shing Chee Lim ...[et al.]

Electrospinning is one of the commonly used polymeric fiber production technique, owing to its versatility and flexibility in spinning a wide range of polymers for various applications including tissue engineering. However, recent researches have been extensively focusing on exploring the electrospinnability of different polymers without fully realizing how the electrospinning parameters influence the electrospun fibrous structure, as the microstructure morphology will significantly affect the performance of electrospun membranes. The present work demonstrates the robustness of electrospinning technique in producing electrospun fibrous membranes with different microstructure morphology by altering the electrospinning parameters. Both PCL and gelatin solutions have been successfully transformed into electrospun fibrous membranes using an electrospinning machine. The PCL fibrous membranes consisted of beads and non-homogenous fibers while the gelatin membranes showed homogenous size of electrospun fibers. Results also revealed that the electrospinning parameters including solution and process parameters determined the microstructure morphology of electrospun membrane. The spindle-like beads in PCL membrane transformed into spherical size at higher solution concentration and applied voltage. Meanwhile, the gelatin membrane demonstrated similar morphology at different tip-collector distance. The size of gelatin fibers was also similar. Through this work, basic understanding on how the electrospinning parameters affect the morphology of different types of polymeric fibrous membrane can provide an insight for other researchers in facilitate production of electrospun membranes with desired microstructure morphology

Release of Pre-Trained Models for the Japanese Language

AI democratization aims to create a world in which the average person can utilize AI techniques. To achieve this goal, numerous research institutes have attempted to make their results accessible to the public. In particular, large pre-trained models trained on large-scale data have shown unprecedented potential, and their release has had a significant impact. However, most of the released models specialize in the English language, and thus, AI democratization in non-English-speaking communities is lagging significantly. To reduce this gap in AI access, we released Generative Pre-trained Transformer (GPT), Contrastive Language and Image Pre-training (CLIP), Stable Diffusion, and Hidden-unit Bidirectional Encoder Representations from Transformers (HuBERT) pre-trained in Japanese. By providing these models, users can freely interface with AI that aligns with Japanese cultural values and ensures the identity of Japanese culture, thus enhancing the democratization of AI. Additionally, experiments showed that pre-trained models specialized for Japanese can efficiently achieve high performance in Japanese tasks.Comment: 9 pages, 1 figure, 5 tables, accepted for LREC-COLING 2024. Models are publicly available at https://huggingface.co/rinn

Nutritional composition of unripe and ripe freeze-dried Terung Asam from Sarawak

This study aimed to assess and compare the nutritional composition between unripe and ripe freeze-dried Terung Asam from Sarawak. Terung Asam was checked for its maturity upon collection. Whole fruits were freeze-dried and used for proximate analyses. The redness/greeness (a*) of unripe and ripe fresh Terung Asam used in this study were -14.20 ± 3.11 and 12.57 ± 1.60 respectively. The moisture content of unripe fresh Terung Asam was significantly higher than ripe fresh Terung Asam (p < 0.05). There were statistically significant differences in crude protein (p < 0.05), crude fat (p < 0.05), ash (p < 0.05) and crude fibre (p < 0.001) between unripe and ripe freeze-dried Terung Asam (UFTA and RFTA respectively). RFTA had higher crude fibre (19.87 ± 0.68g/100g) and ash (6.20 ± 0.18g/100g) than UFTA (13.86 ± 0.58g/100g crude fibre, 5.43 ± 0.12g/100g ash). In contrast, UFTA was higher in protein (10.77 ± 0.30g/100g) and fat (0.74 ± 0.05g/100g) than RFTA (9.43 ± 0.40g/100g crude protein, 0.48 ± 0.08g/100g fat). The results of this study suggested that whole fruits of UFTA and RFTA were good source of crude protein, crude fibre and mineral. The data gathered from this research can contribute to the body of knowledge of this underutilized indigenous fruit as well as becoming useful for future product development using Terung Asam

Gelsolin induces colorectal tumor cell invasion via modulation of the urokinase-type plasminogen activator cascade

Gelsolin is a cytoskeletal protein which participates in actin filament dynamics and promotes cell motility and plasticity. Although initially regarded as a tumor suppressor, gelsolin expression in certain tumors correlates with poor prognosis and therapy-resistance. In vitro, gelsolin has anti-apoptotic and pro-migratory functions and is critical for invasion of some types of tumor cells. We found that gelsolin was highly expressed at tumor borders infiltrating into adjacent liver tissues, as examined by immunohistochemistry. Although gelsolin contributes to lamellipodia formation in migrating cells, the mechanisms by which it induces tumor invasion are unclear. Gelsolin’s influence on the invasive activity of colorectal cancer cells was investigated using overexpression and small interfering RNA knockdown. We show that gelsolin is required for invasion of colorectal cancer cells through matrigel. Microarray analysis and quantitative PCR indicate that gelsolin overexpression induces the upregulation of invasion-promoting genes in colorectal cancer cells, including the matrix-degrading urokinase-type plasminogen activator (uPA). Conversely, gelsolin knockdown reduces uPA levels, as well as uPA secretion. The enhanced invasiveness of gelsolin-overexpressing cells was attenuated by treatment with function-blocking antibodies to either uPA or its receptor uPAR, indicating that uPA/uPAR activity is crucial for gelsolin-dependent invasion. In summary, our data reveals novel functions of gelsolin in colorectal tumor cell invasion through its modulation of the uPA/uPAR cascade, with potentially important roles in colorectal tumor dissemination to metastatic sites