Publications by authors named "Opara E"

Article Synopsis
  • - The study investigates the impact of hepatic growth factor (HGF) on the secretion of small extracellular vesicles (sEV) from urine-derived stem cells (USCs), focusing on two methods of HGF delivery: bolus administration and controlled release using alginate microbeads.
  • - Results indicate that the group receiving HGF through controlled release from microbeads showed a significantly higher concentration of proteins and sEV compared to both the bolus and control groups after 7 days.
  • - The findings suggest that using a controlled release method for HGF significantly boosts sEV secretion from USCs, which could have implications for tissue regeneration and protection.
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Lower urinary tract dysfunction (LUTD) encompasses a range of debilitating conditions that affect both sexes and different age groups. Understanding the underlying neurobiological mechanisms contributing to LUTD has emerged as a critical avenue for the development of targeted therapeutic strategies. Brain-derived neurotrophic factor (BDNF), a prominent member of the neurotrophin family, has attracted attention due to its multiple roles in neural development, plasticity, and maintenance.

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A strategy that seeks to combine the biophysical properties of inert encapsulation materials like alginate with the biochemical niche provided by pancreatic extracellular matrix (ECM)-derived biomaterials, could provide a physiomimetic pancreatic microenvironment for maintaining long-term islet viability and function in culture. Herein, we have demonstrated that incorporating human pancreatic decellularized ECM within alginate microcapsules results in a significant increase in Glucose Stimulation Index (GSI) and total insulin secreted by encapsulated human islets, compared to free islets and islets encapsulated in only alginate. ECM supplementation also resulted in long-term (58 days) maintenance of GSI levels, similar to that observed in free islets at the first time point (day 5).

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Tissue-engineering and cell-based strategies provide an intriguing approach to treat complex conditions such as those of the endocrine system. We have previously developed a cell-based hormone therapy (cHT) to address hormonal insufficiency associated with the loss of ovarian function. To assess how the cHT strategy may achieve its efficacy, we developed a mathematical model to determine if known autocrine, paracrine, and endocrine effects of the native hypothalamus-pituitary-ovary (HPO) axis could explain our previously observed effects in ovariectomized rats following treatment with cHT.

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There is an unrelenting interest in the development of a reliable bioartificial pancreas construct since the first description of this technology of encapsulated islets by Lim and Sun in 1980 because it promised to be a curative treatment for Type 1 Diabetes Mellitus (T1DM). Despite the promise of the concept of encapsulated islets, there are still some challenges that impede the full realization of the clinical potential of the technology. In this review, we will first present the justification for continued research and development of this technology.

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Diabetes is an epidemic in the United States and is ranked as the sixth leading cause of death in the District of Columbia. According to the US Census population in 2010, >52,000 out of 610,000 residents have been diagnosed with diabetes. The highest prevalence was noted in wards 4, 5, 7, and 8, with the worst impact recorded in ward 8.

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Exosomes are enclosed within a single outer membrane and exemplify a specific subtype of secreted vesicles. Exosomes transfer signalling molecules, including microRNAs (miRNAs), messenger RNA (mRNA), fatty acids, proteins, and growth factors, making them a promising therapeutic tool. In routine bioartificial pancreas fabrication, cells are immobilized in polymeric hydrogels lacking attachment capability for cells and other biological cues.

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In this research we have used different cytokines and progesterone to enhance the immunomodulatory capacity of placental-derived stem cells (PLSCs) prior to their encapsulation. We assessed the effect of microencapsulation of the cells without (control) or after 3-day treatment with interferon gamma (INFγ), interleukin10 (IL-10), or progesterone (P4). Treated PLSCs demonstrated strong immunosuppressive effects on phytohemagglutinin (PHA)-activated peripheral blood mononuclear cells (PBMNCs).

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In this minireview, we briefly outline the hallmarks of diabetes, the distinction between type 1 and type 2 diabetes, the global incidence of diabetes, and its associated comorbidities. The main goal of the review is to highlight the great potential of encapsulated pancreatic islet transplantation to provide a cure for type 1 diabetes. Following a short overview of the different approaches to islet encapsulation, we provide a summary of the merits and demerits of each approach of the encapsulation technology.

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Background: The Slit-Robo pathway is a key regulator of angiogenesis and cellular function in experimental models. Slit3 proteins exhibit both proangiogenic and antiangiogenic properties, but the exact mechanism remains unclear. It is theorized that Slit3 may be a potential treatment for vascular diseases and cancer.

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Interactions between the pancreatic extracellular matrix (ECM) and islet cells are known to regulate multiple aspects of islet physiology, including survival, proliferation, and glucose-stimulated insulin secretion. Recognizing the essential role of ECM in islet survival and function, various engineering approaches have been developed that aim to utilize ECM-based materials to recreate a native-like microenvironment. However, a major impediment to the success of these approaches has been the lack of a robust and comprehensive characterization of the human pancreatic proteome.

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Islet transplantation is emerging as a therapeutic option for type 1 diabetes, albeit, only a small number of patients meeting very stringent criteria are eligible for the treatment because of the side effects of the necessary immunosuppressive therapy and the relatively short time frame of normoglycemia that most patients achieve. The challenge of the immune-suppressive regimen can be overcome through microencapsulation of the islets in a perm-selective coating of alginate microbeads with poly-l-lysine or poly- l-ornithine. In addition to other issues including the nutrient supply challenge of encapsulated islets a critical requirement for these cells has emerged as the need to engineer the microenvironment of the encapsulation matrix to mimic that of the native pancreatic scaffold that houses islet cells.

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Islet transplantation (ITx) has the potential to become the standard of care in beta cell replacement medicine but its results remain inferior to those obtained with whole pancreas transplantation. The protocols currently used for human islet isolation are under scrutiny because they are based on the enzymatic digestion of the organ, whereby the pancreas is demolished, its connections to the body are lost and islets are irreversibly damaged. Islet damage is characterized by critical factors such as the destruction of the extracellular matrix (ECM), which represents the 3D framework of the islet niche and whose loss is incompatible with islet euphysiology.

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Ethnopharmacological Relevance: The Zulu and Xhosa people of South Africa use the stem bark of Cassipourea flanaganii as a skin-lightning cosmetic.

Aim Of The Study: To isolate and identify compounds responsible for the skin lightning properties from the stem bark of Cassipourea flanaganii and to evaluate their cytotoxicity towards skin cells.

Materials And Methods: Extracts from the stem bark of Cassipourea flanaganii were isolated using chromatographic methods and structures were determined using NMR, IR and MS analysis.

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Background: There is a significant interest in effective oral drug delivery of therapeutic substances. For probiotics, there is a particular need for a delivery platform that protects the bacteria from destruction by the acidic stomach while enabling targeted delivery to the intestine where microbiota naturally reside. The use of probiotics and how they impact the gut microbiota is a growing field and holds promise for the treatment of a variety of gastrointestinal diseases, including irritable bowel disease Crohn's disease and C.

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Article Synopsis
  • There's a growing demand for effective ways to encapsulate transplanted cells using high-throughput technologies, and microfluidics stands out as a promising option.
  • Traditional microfluidic devices often face issues like clogging and high costs, which limit their effectiveness for these applications.
  • This research introduces a new reusable microfluidic device that creates high-quality alginate hydrogel microbeads, demonstrating successful long-term cell encapsulation with maintained viability, making the process scalable for various uses.
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Here, we report two methods that chemically modify alginate to achieve neutral-basic pH sensitivity of the resultant hydrogel. The first method involves direct amide bond formation between alginate and 4-(2-aminoethyl)benzoic acid. The second method that arose out of the desire to achieve better control of the degradation rate of the alginate hydrogel involves reductive amination of oxidized alginate.

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Genetics has long been considered to associate with many exercise-related traits and sport performance phenotypes. A genetic basis for elite international marathon running performance exists due to the heritability of endurance-related traits. This has prompted a generation of genomic study to identify marathon success.

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Culinary herbs and spices (CHS) are known primarily as flavour enhancers, and it is now well established that they possess bioactive properties that indicate that these foods may have a role to play in the prevention of non-communicable chronic diseases (CNCDs). Human studies are now beginning to provide insights into the significance of the potential health benefits of CHS in a dietary context, particularly concerning their antioxidant and anti-inflammatory properties and their impact on glucose homeostasis, appetite and the consumption of low/reduced fat, salt and sugar foods. However, these studies have also identified a number of factors that are very pertinent to furthering understanding of how CHS can be used for the maintenance of health and the prevention of CNCDs.

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Currently, islet isolation is performed using harsh collagenases that cause nonspecific injury to both islets and exocrine tissue, negatively affecting the outcome of cell transplantation. We evaluated a novel islet isolation protocol utilizing high concentrations of glucose to cause selective osmotic shock (SOS). Islets have a membrane glucose transporter that allows adaptation to changes in glucose concentrations while exocrine tissue can be selectively destroyed by these osmolar shifts.

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Safe clinical hormone replacement (HR) will likely become increasingly important in the growing populations of aged women and cancer patients undergoing treatments that ablate the ovaries. Cell-based HRT (cHRT) is an alternative approach that may allow certain physiological outcomes to be achieved with lower circulating hormone levels than pharmacological means due to participation of cells in the hypothalamus-pituitary-ovary feedback control loop. Here we describe the in vivo performance of 3D bioengineered ovarian constructs that recapitulate native cell-cell interactions between ovarian granulosa and theca cells as an approach to cHRT.

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Type-1 Diabetes (T1D) is a devastating autoimmune disorder which results in the destruction of beta cells within the pancreas. A promising treatment strategy for T1D is the replacement of the lost beta cell mass through implantation of immune-isolated microencapsulated islets referred to as the bioartificial pancreas. The goal of this approach is to restore blood glucose regulation and prevent the long-term comorbidities of T1D without the need for immunosuppressants.

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