Significance of Nestin and CD133 as cancer stem cell markers in diffuse glioma and association with p53 expression and IDH status.

BACKGROUND: Recent evidence suggests that the tumor stem cells that are responsible for the pathogenesis of gliomas have similar properties to those of neural stem cells. We have studied two of the most consistently expressed stem cell markers in gliomas, i.e., CD133 and Nestin, and compared them with respect to p53 expression and IDH status. OBJECTIVES: To assess the level of expression of Nestin and CD133, and identify a correlation among various grades of diffuse glioma with IDH status and expression of p53. MATERIALS AND METHODS: A cross-sectional retrospective study with 102 subjects for the expression of cancer stem cell markers; CD133 and Nestin and the correlation of their expression with that of p53 and IDH1 status in adult diffuse glioma. The study was conducted in the Departments of Pathology and Neurosurgery. The expression was assessed by immunohistochemistry on formalin-fixed paraffin-embedded sections. The scoring of expression of CD133 and Nestin was adapted from Zhang et al. The scoring for p53 was adopted from Aruna et al. Results: The diffuse gliomas were graded based on WHO into grade II (30.3%), grade III (28.4%), and grade IV (41.3%). Among WHO grade IV, 59.4% were primary, and 40.4% were secondary glioblastomas. 73% of the diffuse gliomas were IDH mutant, and p53 showed an overall expression of 76.4%. The expression of CD133 and Nestin were compared with the increasing grades of diffuse gliomas, which, when plotted on ROC curves, had AUCs of 0.6806 and 0.6119, respectively. Their expression showed a positive correlation with the IDH status of the tumor. CONCLUSIONS: Cancer stem cell markers CD133 and Nestin are expressed in diffuse glioma and have a higher expression with increasing WHO grade of malignancy. These cancer stem cell markers have shown significant association with the IDH-1 mutant status of diffuse gliomas. Hence, it can be inferred that diffuse gliomas with a higher expression of CD133 and Nestin have a poorer prognosis. Further, these cancer stem cell markers may be used as therapeutic targets in the future.

Hepatic Expression of NTN4 and Its Receptors in Patients with Hepatocellular Carcinoma.

BACKGROUND: Angiogenesis contributes to hepatocellular carcinoma (HCC) progression by promoting tumor growth and metastasis. Netrin-4 (NTN4) is a secreted glycoprotein that has been reported to control angiogenesis and preserve endothelial homeostasis. Macrovascular invasion of the portal vein, referred to as portal vein invasion (PVI) is associated with poor prognosis in HCC patients. In this work, we sought to understand more about the systemic and hepatic level expression of NTN4 and its receptors in HCC patients with and without portal vein invasion. METHODS: A total of 154 patients with HCC, and 90 healthy volunteers were recruited in this case-control study. Patients with HCC were further subdivided into those with portal vein invasion (PVI) (n=68), and those without portal vein invasion (NPVI) (n=86). Clinical characteristics and liver function parameters were recorded among the study subjects PVI and NPVI. The serum levels of NTN4 (pg/ml) were estimated by ELISA. HCC tissues and normal non-tumorous liver tissues (controls) were collected for gene expression analysis of NTN4 and its receptors. RESULTS: ALT, ALP, and GGT levels were significantly elevated in the serum of HCC patients with PVI compared to NPVI and control subjects. Systemic NTN4 was significantly reduced in both PVI and NPVI patients compared to control subjects. At the tissue level, the hepatic NTN4 followed a similar trend with significantly lower mRNA expression in both patients with PVI and NPVI compared to control subjects. CONCLUSIONS: Systemic and hepatic NTN4 levels were reduced in both PVI and NPVI subjects. The hepatic expression of NTN4 receptors Neogenin and UNC5B were markedly elevated in patients with HCC with PVI compared to NPVI. Future experimental studies might shed the role of NTN4 and its receptors in the development of PVI in HCC.

A study on H-score threshold for p16ink4a immunoperoxidase expression in squamous cell tumours of oral cavity.

Background: Validity of various detection methods used are likely contributing factor to this wide variation of prevalence of HPV (0-73%) by using GP5/GP6/MY09/MY11 (L1) primer. PCR is a sensitive method but does not identify transcriptionally active High-risk Human papillomavirus and also does not indicate whether the virus is isolated from malignant tumour cells and non-neoplastic cells. P16ink4a Immunohistochemistry is a highly sensitive and Cost-effective surrogate marker for transcriptionally active high-risk HPV for oral cancer. Objective The aim of the present study was to evaluate the H-SCORE of p16 expression in the surface epithelial tumour sites of a large cohort of squamous cell carcinoma (SCC), severe dysplasia (SD). we sought to determine whether the p16 algorithm is reliable in Oral cavity SCC and severe dysplasia (SD). Materials and Methods: This study used Immunohistochemistry in archival Formalin-fixed paraffin embedded specimens for assessment of p16 protein expression, cytoplasmic and nuclear staining intensity was categorized based on score (range, 0-3) and presence of tumour cell staining (0-100%). Results: The majority of positive cases had low H-score of p16 staining except 3/161 (1.8%) cases of tongue SCC had positive for p16 with diffuse moderate staining with ≥2 scores. There were no significant differences in the distribution of demographic, exposure and histopathological characteristics between patients with and without P16 expression. Conclusion: The present study demonstrated that p16 expression is a reliable HPV marker in the lateral border of the tongue with tonsil involvement but no other sites of the oral cavity. Further p16 IHC detection is required in large cohort of all sites of tongue squamous cell carcinoma studies to validate the marker of HPV.

Serum Levels of Netrin-4 and Its Association With Hepatocellular Carcinoma: Results From a Case-Control Study.

BACKGROUND: Angiogenesis plays a vital role in the progression of hepatocellular carcinoma (HCC) by contributing to tumor growth and metastasis. Netrin-4 (NTN4) is a secreted glycoprotein that regulates angiogenesis and maintains endothelial homeostasis. There were no studies found focusing on the value of NTN4 as a serum biomarker for the diagnosis and prognosis of HCC. In this study, we aimed to investigate the systemic expression of NTN4 in patients with HCC. We also explore the association of NTN4 with major clinicopathological and biochemical characteristics of HCC. METHODS: A total of 116 patients with HCC and 44 healthy volunteers were recruited in this case-control study. Clinical characteristics and liver function parameters were recorded among the study subjects. The levels of α-fetoprotein (AFP) were quantified in patients with HCC. The serum levels of NTN4 (pg/ml) were estimated by enzyme-linked immunosorbent assay (ELISA). RESULTS: The median NTN4 levels were significantly decreased in patients with HCC when compared to control subjects (p < 0.0001). There was no difference between NTN4 levels in AFP-positive patients and AFP-negative patients (p = 0.39). Of note, NTN4 levels were significantly decreased in HCC patients with metastasis (p < 0.02) and portal vein invasion (p < 0.04). Further, NTN4 levels were significantly reduced in HCC patients with Child-Pugh C score (p < 0.05). The receiver operating characteristic curve for serum levels of NTN4 in the HCC group and control group was generated. At a cut-off of 30 pg/ml, the sensitivity and specificity for NTN4 were 80% and 82%, respectively, with an AUC of 0.894. CONCLUSIONS: Low levels of NTN4 were associated with increased tumor aggressiveness and metastasis in HCC. Estimation of circulating NTN4 has prognostic value as a minimally invasive biomarker in HCC. Future studies might shed the role of NTN4 in the development of HCC.

Loading and Release of Quercetin from Contact-Drawn Polyvinyl Alcohol Fiber Scaffolds.

Polymeric drug releasing systems have numerous applications for the treatment of chronic diseases and traumatic injuries. In this study, a simple, cost-effective, and scalable method for dry spinning of crosslinked polyvinyl alcohol (PVA) fibers is presented. This method utilizes an entangled solution of PVA to form liquid bridges that are drawn into rapidly drying fibers through extensional flow. The fibers are crosslinked by a one-pot reaction in which glyoxal is introduced to the PVA solution prior to contact drawing. Failure analysis of fiber formation is used to understand the interplay of polymer concentration, glyoxal concentration, and crosslinking time to identify appropriate formulations for the production of glyoxal-crosslinked PVA fibers. The small molecule quercetin (an anti-inflammatory plant flavonoid) can be added to the one-pot reaction and is shown to be incorporated into the fibers in a concentration-dependent manner. Upon rehydration in an aqueous medium, the glyoxal-crosslinked PVA fiber scaffolds retain their morphology and slowly degrade, as measured over the course of 10 days. As the scaffolds degrade, they release the loaded quercetin, reaching a cumulative release of 56 ± 6% of the loaded drug after 10 days. The bioactivity of the released quercetin is verified by combining quercetin-loaded fibers with contact-drawn polyethylene oxide-type I collagen (PEO-Col) fibers and monitoring the growth of PC12 cells on the fibers. PC12 cells readily attach to the PEO-Col fibers and display increased nerve growth factor-induced elongation and neurite formation in the presence of quercetin-loaded PVA fibers relative to substrates formed from only PEO-Col fibers or PEO-Col and PVA fibers without quercetin.

Multi-pin contact drawing enables production of anisotropic collagen fiber substrates for alignment of fibroblasts and monocytes.

Type I collagen is the most abundant protein in the human body and is known to play important roles in numerous biological processes including tissue morphogenesis and wound healing. As such, it is one of the most frequently used substrates for cell culture, and there have been considerable efforts to develop collagen-based cell culture substrates that mimic the structural organization of collagen as it is found in native tissues, i.e., collagen fibers. However, producing collagen fibers from extracted collagen has been notoriously difficult, with existing methods providing only low throughput production of collagen fibers. In this study, we prepared collagen fibers using a highly efficient, bio-friendly, and cost-effective approach termed contact drawing, which uses an entangled polymer fluid to aid in fiber formation. Contact drawing technology has been demonstrated previously for collagen using highly concentrated dextran solutions with low concentrations of collagen. Here, we show that by replacing dextran with polyethylene oxide (PEO), high collagen content fibers may be readily formed from mixtures of soluble collagen and PEO, a polymer that readily forms fibers by contact drawing at concentrations as low as 0.5%wt. The presence of collagen and the formation of well-ordered collagen structures in the resulting fibers were characterized by attenuated total reflectance Fourier-transform infrared spectromicroscopy, Raman spectromicroscopy, and fluorescence microscopy. Corresponding to well-ordered collagen, the mechanical properties of the PEO-collagen fibers approximated those observed for native collagen fibers. Growth of cells on aligned PEO-collagen fibers attached to a polydimethyl siloxane support was examined for human dermal fibroblast (WS1) and human peripheral leukemia blood monocyte (THP-1) cell lines. WS1 and THP-1 cells readily attached, displayed alignment through migration and spreading, and proliferated on the collagen fiber substrate over the course of several days. We also demonstrated the retrieval of viable cells from the PEO-collagen fiber substrates through enzymatic digestion of the collagen substrate with collagenase IV.

Gastric adenocarcinoma presenting with multiple skeletal muscle metastases.

A 42-year-old man presented to the gastroenterology clinic with features of gastric outlet obstruction, significant weight loss, anaemia, ascites, and pain in the lower back and left thigh. CT scan of the abdomen and pelvis showed wall thickening in the antropyloric region of the stomach and enhancing soft tissue lesion in the left psoas and right gluteal region. Gastroscopy revealed a circumferential growth in the antrum and pylorus of the stomach, and biopsy from the growth was reported as moderately differentiated adenocarcinoma. Positron emission tomography-CT scan showed multiple skeletal muscle metastases all over the body. Fine-needle aspiration cytology and immunohistochemistry from the psoas lesion confirmed metastatic adenocarcinoma deposits. He underwent antropyloric stenting for his obstructive symptoms and received supportive care, finally succumbed to his illness after 6 weeks.

Sister Mary Joseph Nodule as an Initial Presentation of Pancreatic Adenocarcinoma.

Sister Mary Joseph (SMJ) nodule is a metastatic umbilical nodule seen in primary tumors of the gastrointestinal or genitourinary tract. The stomach and colon are the common gastrointestinal cancers associated with SMJ nodule. The pancreas is a rare primary site for umbilical metastasis. Moreover, malignant umbilical nodules as the first presentation in pancreatic cancer is rare. Pancreatic adenocarcinoma that metastasizes to umbilicus usually arise from the body or tail of the pancreas. The presence of SMJ nodule usually indicates poor prognosis. Umbilical nodule is a simple physical finding to the presence of an advanced intra-abdominal malignancy. Although rare, pancreatic cancer should be considered as one of the primary sites in such a situation.

Pathological abnormalities in splenic vasculature in non-cirrhotic portal hypertension: Its relevance in the management of portal hypertension.

BACKGROUND: Portal hypertension (PH) is associated with changes in vascular structure and function of the portosplenomesenteric system (PSMS). This is referred to as portal hypertensive vasculopathy. Pathological abnormalities of PSMS has been described in the literature for cirrhotic patients. Raised portal pressure and hyperdynamic circulation are thought to be the underlying cause of this vasculopathy. In view of this, it is expected that pathological changes in splenic and portal vein similar to those reported in cirrhotic patients with PH may also be present in patients with non-cirrhotic PH (NCPH). AIM: To investigate pathological abnormalities of splenic vein in patients with NCPH, and suggest its possible implications in the management of PH. METHODS: A prospective observational study was performed on 116 patients with NCPH [Extrahepatic portal vein obstruction (EHPVO): 53 and non-cirrhotic portal fibrosis (NCPF): 63] who underwent proximal splenorenal shunt (PSRS), interposition shunt or splenectomy with devascularization in JIPMER, Pondicherry, India, a tertiary level referral center, between 2011-2016. All patients were evaluated by Doppler study of PSMS, computed tomography porto-venogram and upper gastrointestinal endoscopy. An acoustic resonance forced impulse (ARFI) scan and abdomen ultrasound were done for all cases to exclude cirrhosis. Intraoperative and histopathological assessment of the harvested splenic vein was performed in all. The study group was divided into delayed and early presentation based on the median duration of symptoms (i.e. 108 mo). RESULTS: The study group comprising of 116 patients [77 (66%) females and 39 (34%) males] with NCPH had a median age of 22 years. Median duration of symptoms was 108 mo. The most common presentation in both EHPVO and NCPF patients was upper gastrointestinal bleeding (hematemesis and melena). The ARFI scan revealed a median score of 1.2 (1.0-1.8) m/s for EHPVO and 1.5 (0.9-2.8) m/s for NCPF. PSRS was performed in 84 patients (two of whom underwent interposition PSRS using a 10 mm Dacron graft); splenoadrenal shunt in 9; interposition mesocaval shunt in 5; interposition 1st jejunal to caval shunt in 1 patient and devascularization with splenectomy in 17 patients. Median pre-splenectomy portal pressure was 25 (range: 15-51) mm Hg. In 77% cases, the splenic vein was abnormal upon intraoperative assessment. Under macroscopic examination, wall thickening was observed in 108 (93%), venous thrombosis in 32 (28%) and vein wall calcification in 27 (23%) cases. Upon examination under a surgical magnification loupe, 21 (18%) patients had intimal defects in the splenic vein. Histopathological examination of veins was abnormal in all cases. Medial hypertrophy was noted in nearly all patients (107/116), while intimal fibrosis was seen in 30%. Ninety one percent of patients with intimal fibrosis also had venous thrombosis. Vein wall calcification was found in 22%, all of whom had intimal fibrosis and venous thrombosis. The proportion of patients with pathological abnormalities in the splenic vein were significantly greater in the delayed presentation group as compared to the early presentation group. CONCLUSION: Pathological changes in the splenic vein similar to those in cirrhotic patients with PH are noted in NCPH. We recommend that PH in NCPH be treated as systemic and pulmonary hypertension equivalent in the gastrointestinal tract, and that early aggressive therapy be initiated to reduce portal pressure and hemodynamic stress to avoid potential lethal effects.

Surface-Functionalized Poly(Ether Sulfone) Composite Hollow Fiber Membranes with Improved Biocompatibility and Uremic Toxins Clearance for Bioartificial Kidney Application.

Bioartificial kidney (BAK) is attracting the focus of the research community. In this study, the efficacy of surface-functionalized poly(ether sulfone)-TPGS-graphene oxide composite hollow fiber membranes as a promising material for the single extracorporeal unit for BAK application was evaluated. The cytotoxicity was examined using human primary renal proximal tubular epithelial cells (hPTCs), and the removal of uremic toxins (urea, creatinine, phosphate, and lysozyme) from the toxin-spiked goat blood was measured. The surface-functionalized polymer composite membranes acted as a biocompatible material for attachment and proliferation of hPTCs, which was confirmed by microscopy studies, proliferation, and activity assays. The functional activity of these renal cells over this biocompatible membrane was also maintained. Remarkably, the functionalized composite membranes showed removal of urea (46.4 ± 3.5%), creatinine (52.2 ± 3.9%), phosphate (35.5 ± 2.7%), and lysozyme (11.2 ± 0.8%) from the toxin-spiked goat blood. Therefore, these obtained results showed that the surface-functionalized poly(ether sulfone)-TPGS-graphene oxide composite hollow fiber membranes are suitable for BAK application.

Polyethersulfone-carbon nanotubes composite hollow fiber membranes with improved biocompatibility for bioartificial liver.

Carbon nanotubes (CNTs) blended hollow fiber membranes (HFMs) are a promising new material in the area of biomedical engineering because they simultaneously provide tunable hydrophilicity along with selective permeability. In the present study, composite polyethersulfone (P) HFMs were fabricated using d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS or T) as compatibilizer, and carboxylated multiwalled CNTs (MWCNTs or C) as filler. The amount of MWCNTs was optimized for the improved hemocompatibility, cell viability, and cellular functionality. An optimum was found with the composte HFMs (PTC-2), where MWCNTs were used at concentration of 0.030 wt.%, as it exhibited improved compatibility with human blood. Further, these PTC-2 HFMs showed enhanced liver (HepG2) cells growth with the enhanced cell functional activities, mainly albumin secretion and glucose consumption. These developed composite membrane can act as a membrane material for liver cell bioreactor and bioartificial liver development because of their 3D scaffold like characteristic which enables cell growth, and selective permeability which helps in immunoisolation.

The Expression of Leptin and Its Receptor During Tumorigenesis of Diffuse Gliomas such as Astrocytoma and Oligodendroglioma- Grade II, III and IV (NOS)

Background: Leptin, an adipocytokine functions via the leptin receptor, OB-Rb that contains an intact intracellular domain and activates the JAK/STAT signalling cascade. It stimulates growth, migration and invasion of cancer cells in vitro potentiating angiogenesis. Recently, the involvement of leptin in tumor progression is being explored. Gliomas exhibit poor prognosis, low survival rates demanding for novel therapeutic regimens resulting in discovery of many potential biomarkers and pharmaceutical targets. We analysed the potential role of leptin and OB-Rb in carcinogenesis of malignant gliomas. Methods: Sixty fresh tissue samples of diffuse gliomas were collected after tumor excision. Real time PCR, immunohistochemical (IHC) analysis and western blot analysis were carried out to assess the expression of leptin and its receptor. Results: The present study demonstrates the expression of leptin and LepR and their involvement in tumor progression. Of the 60 cases, 57 cases (95%) and 53 cases (88.3%) showed amplification for leptin and OB-Rb respectively. The expression of these proteins were measured semi-quantitatively and correlated with degree of malignancy (p<0.05). The bands were visualised on western blot. Conclusion: Leptin may be valued as a pharmaceutical target and anti-leptin compounds could be developed as drugs in mono- or combined therapies for these tumors.

Hydrophilic ZIF-8 decorated GO nanosheets improve biocompatibility and separation performance of polyethersulfone hollow fiber membranes: A potential membrane material for bioartificial liver application.

The hydrophobic nature of zeolitic imidazole framework-8 (ZIF-8) nanoparticles restricts their use as additives in hollow fiber membranes (HFMs) for biomedical applications. In this study, hydrophilic ZIF-8 decorated graphene oxide nanosheets (ZGs) were synthesized and used as additives (0-1 wt%) in polyethersulfone (P) HFMs with the aim of improving the biocompatibility and separation performance so as to make the ZGP HFMs suitable for bioartificial liver (BAL) application. Elemental mapping and Fourier transform infrared studies confirmed the efficacious incorporation of ZG nanohybrids in the ZGP HFMs, which resulted in their improved hydrophilicity. The remarkably improved biocompatibility was experimentally demonstrated for the ZGP HFMs, which also were antioxidative and hemocompatible. There was a significantly high attachment and proliferation of HepG2 cells on these HFMs, and they showed remarkably high urea synthesis and albumin secretion. Further, the ZGP HFMs showed high ultrafiltration coefficient (392.2 ±â€¯26.5 mL/h/m2/mm Hg), high flux recovery ratio (84.3%), low flux reduction (15.7%), and desirable molecular weight cutoff (125-135 kDa). Thus, these results experimentally demonstrated that the hydrophilic ZG nanohybrids improve the desirable properties of ZGP HFMs making them a potential biocompatible material for biomedical applications including BAL application.

Extracellular matrix-coated polyethersulfone-TPGS hollow fiber membranes showing improved biocompatibility and uremic toxins removal for bioartificial kidney application.

In this study, L-3, 4-dihydroxyphenylalanine and human collagen type IV were coated over the outer surface of the custom-made hollow fiber membranes (HFMs) with the objective of simultaneously improving biocompatibility leading to proliferation of human embryonic kidney cells-293 (HEK-293) and improving separation of uremic toxins, thereby making them suitable for bioartificial kidney application. Physicochemical characterization showed the development of coated HFMs, resulting in low hemolysis (0.25 ±â€¯0.10%), low SC5b-9 marker level (7.95 ±â€¯1.50 ng/mL), prolonged blood coagulation time, and minimal platelet adhesion, which indicated their improved human blood compatibility. Scanning electron microscopy and confocal laser scanning microscopy showed significantly improved attachment and proliferation of HEK-293 cells on the outer surface of the coated HFMs, which was supported by the results of glucose consumption and MTT cell proliferation assay. The solute rejection profile of these coated HFMs was compared favorably with that of the commercial dialyzer membranes. These coated HFMs showed a remarkable 1.6-3.2 fold improvement in reduction ratio of uremic toxins as compared to standard dialyzer membranes. These results clearly demonstrated that these extracellular matrix-coated HFMs can be a potential biocompatible substrate for the attachment and proliferation of HEK-293 cells and removal of uremic toxins from the simulated blood, which may find future application for bioartificial renal assist device.

Functionally coated polyethersulfone hollow fiber membranes: A substrate for enhanced HepG2/C3A functions.

Hollow fiber membrane (HFM) based liver assist systems are a life-saving bridge for patients until a donor organ is available for transplantation or until liver regeneration. However, liver cell attachment and functional maintenance on HFM surface is a major challenge in bio-artificial liver (BAL) support systems. In the present study, novel glutaraldehyde (GTA)-crosslinked gelatin (gel)-coated polyethersulfone (X-gel-PT) HFMs were manufactured using triple orifice spinneret by the dry-wet spinning method. HFMs were characterized for morphology, outer surface roughness, hydrophilicity, tensile strength, thermal stability, BET surface area and pore volume measurements, permeability and rejection. Fourier transform infrared spectroscopy, and transmission electron microscopy confirmed the GTA-crosslinked gel-coating in the X-gel-PT HFMs, which provided the desirable extracellular matrix-like environment to the HepG2/C3A cells. The results of in-vitro hemocompatibility tests showed the better suitability of the developed HFMs for the blood-contact application. X-gel-PT HFMs showed significantly better cellular attachment and proliferation of HepG2/C3A cells on day 3 and 6, as shown by scanning electron and confocal microscopy. Significantly high urea synthesis and albumin secretion seen indicated the improved functional and metabolic activity of HepG2/C3A cells. Thus, the developed X-gel-PT HFMs is a suitable substrate for the hepatocyte culture, mass culture, and development of BAL support system.

Graphene oxide-doping improves the biocompatibility and separation performance of polyethersulfone hollow fiber membranes for bioartificial kidney application.

HYPOTHESIS: Graphene oxide (GO)-doping in polyethersulfone hollow fiber membranes (PES HFMs) improves the biocompatibility and separation performance for bioartificial kidney (BAK) application. EXPERIMENTS: GO was doped in PES HFMs. The physicochemical characterization of the developed HFMs was carried out. The biocompatibility tests including hemocompatibility and cytotoxicity tests, and separation experiments including uremic toxins clearance were performed. FINDINGS: GO-doping resulted in low hemolysis (0.37 ±â€¯0.15%), prolonged coagulation times, and low SC5b-9 marker level (6.84 ±â€¯1.7 ng/mL), i.e., significantly improved hemocompatibility of GP HFMs. The monolayer attachment and improved proliferation of kidney cells on the outer surface of GP HFMs were achieved. GO-doping significantly enhanced the separation performance, i.e., high pure water permeability (154 ±â€¯3 mL/m2/h/mmHg) was measured, and similar solute rejection profile as that of the commercial dialyzer membranes was recorded. The clearance of urea, creatinine and phosphorous from the simulated blood was measured to be almost 1.6 to 3.3 times higher than that measured for the commercial membranes. Thus, these results indicated that the GO-doping remarkably improved the performance of the developed GP HFMs thereby making them a potential membrane material for the BAK application.

Three-dimensional multiscale fiber matrices: development and characterization for increased HepG2 functional maintenance for bio-artificial liver application.

The development of a cell-growth substrate that provides a nature-like microenvironment, promotes cell adhesion, and maintains the cells' functional activities is a research focus in the field of tissue engineering. In the present study, three-dimensional micro-nano multiscale fiber-based substrates were developed by depositing biocompatible polycaprolactone (PCL)/PCL-Chitosan (C)/PCL-C-Gelatin (G) electrospun nanofibers (NFs) on the outer surface of hollow fiber membranes (HFMs) in one step. A comparison study with regard to physico-chemical characterization, hemocompatibility, cytotoxicity, and cellular functionality was performed with the developed matrices. The PCL-C-G NFs-deposited HFMs-based matrix showed superior hemocompatibility for blood-contact applications. The cytotoxicity of these matrices was found to be minimal. HepG2 cells exhibited an exceptionally robust adherence and proliferated growth on the matrix with the formation of characteristic multi-cellular spheroids. Furthermore, cell functional activities such as albumin secretion, urea synthesis, and cytochrome P450 specific activity were measured for the developed matrices. The developed three-dimensional multiscale fibers-based matrix can be a potential membrane for bioreactor and bio-artificial liver applications.

Improved hemodialysis with hemocompatible polyethersulfone hollow fiber membranes: In vitro performance.

We show that addition of nanozeolite (NZ) and vitamin E D-α-Tocopherol polyethylene glycol succinate (TPGS or T) considerably improves the performance of polyethersulfone (PES or P) hollow fiber membrane (HFM) for hemodialysis. Nanocomposite HFMs were manufactured using PES as a polymer, TPGS as an additive and NZ as a filler to give a composite membrane called PT-NZ. HFMs were spun by dry-wet spinning principle based on liquid-liquid phase separation. TPGS and NZ were successfully incorporated in HFMs, as confirmed by EDX elemental mapping. The resultant PT-NZ HFMs had improved hemocompatibility: lower percent hemolysis (0.28% in batch mode and 0.32% in continuous mode), lower platelet adhesion, higher coagulation time and lower protein adsorption (16.34 µg/cm2 ), compared with P, PT, and commercial (F60S) HFMs. The ultrafiltration coefficient of PT-NZ HFM-based module (274.59 mL/m2 /h/mmHg) was ∼1.5-times higher than that of F60S membranes (151.67 mL/m2 /h/mmHg), and the solute rejection of both the membranes was comparable. The toxin clearance performance of lab-scale PT-NZ HFM-based hemodialyzer with uremic toxin spiked goat blood was remarkably higher (five times) than that of F60S. Hence, the synthesized PT-NZ HFMs are a potentially attractive membrane material for hemodialysis application, particularly due to decreased treatment time and minimal side reactions. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1286-1298, 2018.

Lactobionic acid-functionalized polyethersulfone hollow fiber membranes promote HepG2 attachment and function.

Surface modification of polyethersulfone hollow fibers, which are important in bio-artificial liver, is increasingly used to improve biocompatibility and promote the adhesion and proliferation of hepatocytes resulting in improved cell functionality. Hepatocytes are anchorage-dependent cells, and membrane surface modification enhances the hepatic cell adhesion and proliferation. Specific interaction of the asialoglycoprotein receptor on hepatocyte cell surfaces with a galactose moiety enhances the attachment of the cells on a biocompatible substrate. In this study, the outer surface of the polyethersulfone (P) hollow fiber membranes (HFMs) was chemically modified by covalent coupling with lactobionic acid (LBA). The energy dispersive X-ray spectrometry elemental mapping, attenuated total reflectance-Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy confirmed the LBA-coupling on the outer surface of P-LBA HFMs. Hemocompatibility study indicated the suitability of the modified membranes with human blood. These membranes showed remarkably improved biocompatibility with human primary mesenchymal stem cells and HepG2 cells. Characteristic multi-cellular spheroids of HepG2 cells were observed under scanning electron and confocal microscopy. HepG2 cell functional activity was measured by quantifying the urea synthesis, albumin secretion and glucose consumption in the culture media, which indicated the improved HepG2 functions. These experimental results clearly suggest the potentiality of these LBA-modified P HFMs as a suitable biocompatible substrate for promoting HepG2 attachment and function leading to their application in bioreactors and bio-artificial liver devices.

Islet encapsulated implantable composite hollow fiber membrane based device: A bioartificial pancreas.

Islets from xeno-sources and islet like clusters derived from autologus stem cells have emerged as alternatives to cadaveric pancreas used for treatment of type 1 diabetes. However, the immuno-isolation of these islets from the host immune system suffers from the issue of biocompatibility and hypoxia. To overcome the issues of immunobarrier biocompatibility, we developed a Polysulfone (Psf)/TPGS composite hollow fiber membrane (HFM) using a hollow fiber spinning pilot plant specially developed for this purpose. Important structural variables such as fiber material, dope composition, dimensions, surface characteristics etc., were precisely engineered and tuned for bioartificial pancreas application. The HFMs were characterized for their morphology, molecular diffusion, selectivity and protein absorption. The optimized Polysulfone(Psf)/TPGS composite HFMs, which contained TPGS, exhibited uniformed structure with low insulin adsorption and high permeability of insulin. The HFM was further studied for the encapsulation and in-vitro growth with porcine and differentiated islets isolated from human umbilical cord Wharton's jelly. To prove their efficacy under in-vivo conditions, the Polysulfone(Psf)/TPGS composite HFMs were encapsulated with either of these isolated cells (porcine islets or islet like cell clusters derived from mesenchymal stem cells isolated from human umbilical cord Wharton's jelly) and they were transplanted in experimental STZ induced diabetic mice. The results showed restoration of normoglycemia for 30days, indicating their ability to respond efficiently to high glucose without immune-rejection. Thus, these results indicate that Polysulfone (Psf)/TPGS composite HFMs can be used as an implantable, immune-competent bioartificial pancreas as a therapy for type 1 diabetes.