Speed of capillary blood flow and d-dimer levels in sickle cell anaemia patients in Calabar, cross river state

Background: The experience of painful episodes of ill health caused by sequelae of erythrocytes sickling, impaired blood flow, hypercoagulation and vaso-occlusion is one of the hallmarks of sickle cell disease. Preventing painful episodes and promoting the physical wellbeing of persons with sickle cell disease is usually a major objective in the management of the condition. The purpose of this study is to investigate capillary blood flow and D-Dimer activities in people with sickle cell anaemia.Methods: A total of 90 subjects (27 males and 63 females) participated in the study, the study comprised of 34 HbSS patients, three were in crisis and thirty-one in steady state, 9 sickle cell carriers (HbAS) and 47 HbAA were control subjects. The haemoglobin phenotype was determined using haemoglobin electrophoresis at alkaline pH (8.6), speed of capillary blood flow was estimated using vascular Doppler ultrasonographic technique and D-Dimer was determined using ELISA method.Results: Results obtained showed that there was a significant variation (p=0.042) in the mean levels D-Dimer among the groups. There was however no significant variations (p>0.05) in the other parameters among the groups. A post hoc analysis of mean D-Dimer in sickle cell patients, sickle cell carriers and controls showed that the sickle cell patients had significantly higher D-Dimer levels compared with controls.Conclusions: Sickle cells patients in steady state had higher D-Dimer levels compared with controls and sickle cell patients in crisis had lower speed of capillary blood flow when compared to sickle cell patients in steady state and controls.

Recombinant Human Bone Morphogenic Protein-2 Immobilized Fabrication of Magnesium Functionalized Injectable Hydrogels for Controlled-Delivery and Osteogenic Differentiation of Rat Bone Marrow-Derived Mesenchymal Stem Cells in Femoral Head Necrosis Repair

Femoral head necrosis (FHN) is a clinically progressive disease that leads to overwhelming complications without an effective therapeutic approach. In recent decades, transplantation of mesenchymal stem cells (MSCs) has played a promising role in the treatment of FHN in the initial stage; however, the success rate is still low because of unsuitable cell carriers and abridged osteogenic differentiation of the transplanted MSCs. Biopolymeric-derived hydrogels have been extensively applied as effective cell carriers and drug vesicles; they provide the most promising contributions in the fields of tissue engineering and regenerative medicine. However, the clinical potential of hydrogels may be limited because of inappropriate gelation, swelling, mechanical characteristics, toxicity in the cross-linking process, and self-healing ability. Naturally, gelated commercial hydrogels are not suitable for cell injection and infiltration because of their static network structure. In this study, we designed a novel thermogelling injectable hydrogel using natural silk fibroin-blended chitosan (CS) incorporated with magnesium (Mg) substitutes to improve physical cross-linking, stability, and cell osteogenic compatibility. The presented observations demonstrate that the developed injectable hydrogels can facilitate the controlled delivery of immobilized recombinant human bone morphogenic protein-2 (rhBMP-2) and rat bone marrow-derived MSCs (rBMSCs) with greater cell encapsulation efficiency, compatibility, and osteogenic differentiation. In addition, outcomes of in vivo animal studies established promising osteoinductive, bone mineral density, and bone formation rate after implantation of the injectable hydrogel scaffolds. Therefore, the developed hydrogels have great potential for clinical applications of FHN therapy.

Immunomodulatory Lectin-like Peptides for Fish Erythrocytes-Targeting as Potential Antiviral Drug Delivery Platforms

One of the challenges of science in disease prevention is optimizing drug and vaccine delivery. Until now, many strategies have been employed in this sector, but most are quite complex and labile. To overcome these limitations, great efforts are directed to coupling drugs to carriers, either of natural or synthetic origin. Among the most studied cell carriers are antigen-presenting cells (APCs), however, red blood cells (RBCs) are positioned as attractive carriers in drug delivery due to their abundance and availability in the body. Furthermore, fish RBCs have a nucleus and have been shown to have a strong involvement in modulating the immune response. In this study, we evaluated the binding of three peptides to rainbow trout RBCs, two lectin-like peptides and another derived from Plasmodium falciparum membrane protein, in order to take advantage of this peptide-RBCs binding to generate tools to improve the specificity, efficacy, immunostimulatory effect, and safety of the antiviral therapeutic or prophylactic administration systems currently used.

TEMPO/TCC as a Chemo Selective Alternative for the Oxidation of Hyaluronic Acid

Hyaluronic acid (HA)-based hydrogels are very commonly applied as cell carriers for different approaches in regenerative medicine. HA itself is a well-studied biomolecule that originates from the physiological extracellular matrix (ECM) of mammalians and, due to its acidic polysaccharide structure, offers many different possibilities for suitable chemical modifications which are necessary to control, for example, network formation. Most of these chemical modifications are performed using the free acid function of the polymer and, additionally, lead to an undesirable breakdown of the biopolymer’s backbone. An alternative modification of the vicinal diol of the glucuronic acid is oxidation with sodium periodate to generate dialdehydes via a ring opening mechanism that can subsequently be further modified or crosslinked via Schiff base chemistry. Since this oxidation causes a structural destruction of the polysaccharide backbone, it was our intention to study a novel synthesis protocol frequently applied to selectively oxidize the C6 hydroxyl group of saccharides. On the basis of this TEMPO/TCC oxidation, we studied an alternative hydrogel platform based on oxidized HA crosslinked using adipic acid dihydrazide as the crosslinker.

Novel method for quantifying cells on carriers and its demonstration during SARS-2 vaccine development

The most effective way to prevent and control infectious disease outbreak is through vaccines. The increasing use of vaccines has elevated the need to establish new manufacturing strategies. One of the major approaches is cell-based production, which creates a need for high cell density to enable higher cell production levels. This has led to development of the technology of cell carriers, including micro and macro cell carriers. To follow the production process, quantifying the number of cells on these carriers is required, as well as the tracking of their viability and proliferation. However, owing to various carriers’ unique structures, tracking the cell’s is challenging using current traditional assays that were originally developed for monolayers of adherent cells. The current “gold standard” method is counting cell nuclei, separating cells from the carrier, staining with crystal violet and visually counting under a microscope. This method is tedious and counts both live and dead cells. A few other techniques were developed but were specific to the carrier type and involved specialized equipment. In this study, we describe a broadly ranging method for counting cells on carriers that was developed and employed as part of the production of a vaccine for use in the SARS-CoV-2 pandemic. The method is based on the Alamar blue dye, a well-known, common marker for cell activity, and was found to be successful in tracking cell adsorption, cell growth and viability on carriers. No separation of the cells from the carriers is needed, nor is any specialized equipment; the method is simple and rapid, and provides comprehensive details necessary for process control of viral vaccine production in cells. This method can be easily implemented in any of a number of cell-based processes and other unique platforms for measuring growth of encapsulated cells.

Relationship of oxidative stress and antioxidant response with vaso-occlusive crisis in sickle cell anaemia

Background: Though sickle cell anaemia (SCA) is known to promote oxidative stress, there is paucity of information on the relationship between oxidative stress and vaso-occlusive crisis (VOC). Objective: This study was undertaken to evaluate the relationship of oxidative stress and antioxidant response with VOC in SCA. Methods: A cross-sectional case-control study was carried out at University of Nigeria Teaching Hospital (UNTH), Itu- ku-Ozalla, Enugu Nigeria involving 116 individuals which included 36 SCA subject, 40 sickle cell carriers (AS) and 40 healthy individuals (AA). Baseline information as well as the frequency of VOC was obtained from the participants and anaemia as well as oxidative stress and antioxidant indices were assessed in blood. Results: Anaemia was prevalent (88.9 %) in SCA individuals compared to AS (52.5%) and AA (47.5 %) individuals. Nitric oxide scavenging (NOS) and superoxide dismutase (SOD) activities as well as glutathione level were significantly (p<0.005) lower while catalase activity was higher in SCA individuals compared to controls (AA and AS). Higher malondialdehyde (MDA) level was associated with very severe VOC while low level of NOS activity was associated with severe VOC in SCA individuals. Conclusion: Sickle cell anaemia exhibited oxidative stress and alteration in the levels of antioxidant indices which was pos- sibly associated with vaso-occlusive crisis. Keywords: Sickle cell anaemia; oxidative stress; antioxidant; vaso-occlusive crisis.