Enzyme immobilization on graft copolymers

Immobilised enzymes can be reused, easily separated from the reaction medium, and are more stable in most of the cases. Despite of these advantages, there are still some problems facing the usage of the immobilised enzyme in industry. One of those problems is diffusion-limitation of both the reactants and the products. This problem becomes even more serious when the products are inhibitors of the enzymes. Different strategies for overcoming this problem have been discussed in this thesis.A new solution to overcome diffusion limitation is based on processing the enzymatic reaction under non-isothermal conditions. In such a bioreactor the enzymes have to be immobilised on a hydrophobic membrane.In this thesis, two enzymes,β-galactosidase and penicillin G acylase have been immobilised onto teflon and nylon membranes. Two grafting techniques have been used to modify the membranes in order to be able to bind the enzyme. These grafting techniques were based on using high-energy radiation as well as chemical modification. Both the grafting technique and enzyme immobilisation method has been optimised. The performance of the membranes has been tested in the non-isothermal bioreactor. A higher activity under non-isothermal conditions was found in comparison to isothermal operation. Furthermore, the application of the non-isothermal conditions is promising for solving the diffusion-limitation problems.</p

Arthroscopic Onlay Suprapectoral Bicipital Tenodesis Using Suture Anchor; A Prospective Cohort Study

Background: The long head of the biceps (LHB) tendon was assumed to be a common source of anterior shoulder pain. The inflammatory pathogenesis was considered to be the commonest. Different modalities of treatment were assigned, including conservative, physical therapy, and surgical. Biceps tenotomy and tenodesis were considered the commonest surgical techniques. Methods: We performed a prospective cohort study on 23 patients who presented with anterior shoulder pain due to pathology in the LHB from June 2019 to December 2021. participants were recruited for arthroscopic suprapectoral tenodesis and followed up at two endpoints; six and 12 months. To detect the clinical and functional outcomes, we used the Constant-Murley score, which included four domains pain, strength, range of motion, and Activities of daily living. Also, we calculated the incidence of the Popeye sign, which represented the rupture of LHB. Results: Patients could have a significant improvement in the Constant-Murley score postoperatively at both six and 12 months compared with the preoperative values, with a postoperative mean of 82.3 (78 - 88) at six months and 85.13 (80 - 91) at 12 months. Also, they achieved significant improvement in each of its components; pain, ADL, stability, and motility at six months compared with the baseline values. Additionally, only three patients developed the Popeye sign. Conclusion: The suprapectoral tenodesis was an effective procedure in the treatment of the pain of the LHB tendon with few side effects. It could significantly improve the Constant-Murley score at both six months and one year

NOVEL SMART pH SENSITIVE CHITOSAN GRAFTED ALGINATE HYDROGEL MICROCAPSULES FOR ORAL PROTEIN DELIVERY: II. EVALUATION OF THE SWELLING BEHAVIOR

Objective: The main objective of this study is to evaluate the swelling behavior of pH sensitive chitosan (CS) grafted alginate (ALG) hydrogel microcapsules and compared with a simple alginate-chitosan mixed polyelectrolyte complex (PEC) to show the benefits of the used covalently grafting technique. In addition, the behavior of the swelling process under physiological conditions to stimulate gastric, colonic and intestinal medium for grafted PEC microcapsules will be investigated as well.Methods: The new pH sensitive hydrogel microcapsules were prepared using grafting to†technique. Swelling studies were conducted in buffer saline solutions with different pHs using wet beads. In addition; the sensitivity of the grafted microcapsules to the change of pH in the simulated gastric fluid (SGF; pH 1.2), (SIF; pH 6.8) and (SCF; pH 7.4) was investigated.Results: It was observed from the swelling studies that sharp phase transition was recognized between pH 3–4. While this transition became broader and recognized between pH 3.0-7.4, where the maximum value of the equilibrium swelling degree was varied depending on the variation of CS concentration from 0.1% to 0.5%, both grafted and mixed microcapsules exhibit higher swelling degree at high pH 6.8 (120%, 100%) respectively.Conclusion: It was clear from all swelling studies that the grafting technique may be a suitable way for large-scale production of pH sensitive alginate–chitosan microcapsules as a potential system for site-specific oral delivery of protein drugs to different regions of the intestinal tract.Â

NOVEL SMART pH SENSITIVE CHITOSAN GRAFTED ALGINATE HYDROGEL MICROCAPSULES FOR ORAL PROTEIN DELIVERY: I. PREPARATION AND CHARACTERIZATION

Objectives: Preparation and characterization of a new pH sensitive chitosan (CS) grafted alginate (ALG) hydrogel microcapsules for the oral delivery of protein.Methods: The pH sensitive hydrogel microcapsules were prepared for the first time using grafting to†technique. Firstly, alginate was activated using Ï-Benzoquinone (PBQ) as a coupling agent to graft Chitosan chains later on. Both of activated and grafted alginate microcapsules were characterized by Fourier transform-Infra red spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and the morphological structures were investigated using Scanning electron microscopy (SEM) examination.Results: It was found that the optimum conditions affecting the activation process and also the swelling degree of the prepared hydrogel microcapsules were 2% ALG, 0.04M PBQ pH10, 45 °C for 2h. In addition, the grafting process depends on the attached amount of PBQ and CS concentration. Maximum grafting efficiency (GE %) and chitosan add-on percentage were 98.6% and 14.8% respectively using 0.3% CS at 40 °C for 3h.Conclusions: Novel pH sensitive hydrogel microcapsules were prepared via grafting of chitosan molecules on to activated alginate backbone. The formulated microcapsules can be applied as a new pH sensitive carrier for protein drugs. Â

Clinical Assessment of the Efficiency of Low Level Laser Therapy in the Treatment of Oral Lichen Planus

BACKGROUND: Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa of uncertain etiology.AIM: To evaluate the effect of using low level laser therapy (LLLT (970 nm Siro laser Advance) for the treatment of symptomatic (OLP).SUBJECTS AND METHODS: The present study was conducted on ten patients suffering from persistent oral lichen planus (OLP).Patients were treated with diode laser (970nm) for the symptomatic relief of pain and burning sensation. The patients were assessed before, during and after the completion of the laser treatment which was done twice weekly for two successive months with maximum of ten sessions. The assessment was performed using visual analogue scale (VAS) and clinical investigation for each patient.RESULTS: Detailed significant reduction in lesion size and showed complete remission of burning sensation and pain. No reported complications or therapy side effects were observed in any of the treated patients.CONCLUSION: Diode laser therapy seems to be an effective adjunctive treatment modality for relieving pain and clinical symptoms of OLP

Interferon therapy shifts natural killer subsets among Egyptian patients with chronic hepatitis C

AbstractNatural killer cells can be divided into five subpopulations based on the relative expression of CD16 and CD56 markers. The majority of natural killer cells are CD56dim, which are considered to be the main cytotoxic effectors. A minority of the natural killer cells are CD56bright, and function as an important source of immune-regulatory cytokines. Shifts of these subsets have been reported in patients with chronic hepatitis C virus infection. We sought to investigate the shift of natural killer subsets among Egyptian patients with chronic HCV and to analyze the influence of interferon therapy on this shift. We applied a flow cytometric analysis of peripheral blood natural killer subsets for 12 interferon-untreated and 12 interferon-treated patients with chronic HCV, in comparison to 10 control subjects. Among interferon-untreated patients, there was a significant reduction of CD56-16+ (immature natural killer) cells. Among interferon-treated patients, the absolute count of natural killer cells was reduced, with expansion of the CD56bright subset and reduction of the CD56dim16+ subset. Natural killer subset counts were not significantly correlated to HCV viral load and were not significantly different among interferon responders and non-responders. In conclusion, HCV infection in Egyptian patients has been observed to be statistically and significantly associated with reduction of the CD56-16+NK subset, while a statistically significant expansion of CD56bright and reduction of CD56dim16+ subsets were observed after interferon therapy. Further studies are required to delineate the molecular basis of interferon-induced shift of natural killer subsets among patients with HCV

The effect of diode laser and topical steroid on serum level of TNF-alpha in oral lichen planus patients

Oral lichen planus (OLP) is a common chronic inflammatory mucosal disease with a multifactorial etiology. It is a T-cell mediated autoimmune disease in which the cytotoxic CD8+T cells trigger apoptosis of the basal cells of oral epithelium. Various treatment regimens have been employed for management of symptomatic OLP. This study was carried out to evaluate the effect of topical steroids as well as laser on the clinical signs and symptoms detected by reticular, atrophic, erosive score (RAE score) and tumor necrosis factor- α (TNF-α) level in the serum of patients with symptomatic OLP. The study was conducted on twenty-four patients (18 females and 6 males) with symptomatic OLP that were allocated into two groups. Each included twelve patients. The first group treated either with diode laser (970nm SIROLaser Advance class IIIb, SIRONA The Dental Company, Germany) twice weekly with maximum of ten sessions while the second group were treated with topical corticosteroids (0.1% triamcinolone acetonide orabase, Kenacort-A Orabase Pomad, DEVA HOLDING A.Ș, Istanbul, Turkey) for four weeks. Corticosteroids group showed less clinical signs and symptoms of reticular, atrophic, erosive RAE score (p=0.02) and TNF-α serum level (p=0.028) than diode laser group with no reported therapy side effects or complications in any of the treated patients. Topical steroids reduce pain, reticular, atrophic, erosive RAE score and TNF-α serum level more than laser treatment. Moreover, laser treatment can be used as an alternative treatment when steroids are contraindicated for the treatment of symptomatic OLP