Mustafa F. Sargon

Chitosan films and hydrogels of chlorhexidine gluconate for oral mucosal delivery

Topical delivery of antimicrobial agents is the most widely accepted approach aimed at prolonging active drug concentrations in the oral cavity. As most antifungals do not posses inherent ability to bind to the oral mucosa, this is best achieved through improved formulations. Chitosan, a partially deacetylated chitin, which is a biologically safe biopolymer, prolongs the adhesion time of oral gels and drug release from them. Chitosan also inhibits the adhesion of Candida albicans to human buccal cells and has antifungal activity. The antifungal agent, chlorhexidine gluconate (Chx), also reduces C. albicans adhesion to oral mucosal cells. The aim of this study was to design a formulation containing chitosan for local delivery of Chx to the oral cavity. Gels (at 1 or 2% concentration) or film forms of chitosan were prepared containing 0.1 or 0.2% Chx and their in vitro release properties were studied. The antifungal activity of chitosan itself as well as the various formulations containing Chx was also examined. Release of Chx from gels was maintained for 3 h. A prolonged release was observed with film formulations. No lag-time was observed in release of Chx from either gels or films. The highest antifungal activity was obtained with 2% chitosan gel containing 0.1% Chx.

Nanoparticle silver ion coatings inhibit biofilm formation on titanium implants

The formation of bacterial biofilm on the surface of implanted metal objects is a major clinical problem. The antibacterial and antifungal effect of silver ions has been long known, and seems to give silver the capability to inhibit biofilm formation. To test the effect of silver ions, 20 New Zealand rabbits had bacteria applied to a screw insertion site at the iliac crest, and were then randomly divided into two groups: Group I, which had silver-coated screws applied, and Group II, which had uncoated titanium screws. After the rabbits were sacrificed on day 28, we examined the screws, the bone adjacent to the screws, and the liver, kidneys, brain and corneas of both groups under transmission (TEM) and scanning electron microscopy (SEM). We also analysed microbiological samples from the screw holes. All silver-coated screws, but only 10% of uncoated titanium screws, were sterile. All tissue samples appeared ultrastructurally normal in both groups. Biofilm formation was inhibited on all silver-coated screws, but all uncoated screws developed a biofilm on their surfaces. Our findings suggest that nanoparticle silver ion-coated implants are as safe as uncoated titanium screws and that they can help prevent both biofilm formation and infection.

Preparation, characterization and in vivo distribution of terbutaline sulfate loaded albumin microspheres

Terbutaline sulfate is widely used as a bronchodilator for the treatment of bronchial asthma, chronic bronchitis and emphysema. As it has a short biological half-life, a long acting terbutaline sulfate formulation is desirable to improve patient compliance. Bovine serum albumin microspheres were prepared by an emulsion polymerization method using glutaraldehyde as the crosslinking agent. All microspheres were spherical and smooth with the mean particle size in the range of 22-30 microm. Drug release from the BSA microspheres displayed a biphasic pattern characterized by an initial fast release, followed by a slower release. The released amount was decreased with an increase in the glutaraldehyde concentration. In the absence of trypsin, the time required for complete degradation of microspheres was increased from 144 to 264 h when the glutaraldehyde concentration increased from 0.1 to 0.7 ml. In the presence of trypsin, a linear relationship was obtained between the degradation rates and trypsin concentrations, indicating that saturation was not reached under the experimental conditions. Biodistribution studies indicated that the degree of uptake by the lungs was higher than that of the other organs. All these results demonstrated that terbutaline sulfate loaded microspheres can be used for passive lung targeting.

Squalenoyl adenosine nanoparticles provide neuroprotection after stroke and spinal cord injury.

There is an urgent need to develop new therapeutic approaches for the treatment of severe neurological trauma, such as stroke and spinal cord injuries. However, many drugs with potential neuropharmacological activity, like adenosine, are inefficient upon systemic administration because of their fast metabolisation and rapid clearance from the bloodstream. Here, we show that the conjugation of adenosine to the lipid squalene and the subsequent formation of nanoassemblies allow a prolonged circulation of this nucleoside, to provide neuroprotection in mouse stroke and rat spinal cord injury models. The animals receiving systemic administration of squalenoyl adenosine nanoassemblies showed a significant improvement of their neurologic deficit score in the case of cerebral ischaemia, and an early motor recovery of the hindlimbs in the case of spinal cord injury. Moreover, in vitro and in vivo studies demonstrated that the nanoassemblies were able to extend adenosine circulation and its interaction with the neurovascular unit. This paper shows, for the first time, that a hydrophilic and rapidly metabolised molecule like adenosine may become pharmacologically efficient owing to a single conjugation with the lipid squalene.

An unusual origin for the accessory head of biceps brachii muscle

During the superficial dissection of the pectoral region and the arm, an abnormal biceps brachii muscle was observed unilaterally. This muscle had three heads. Whereas the short and long heads had their normal origin, the accessory head originated from the anterior surface of the distal part of the pectoralis major muscle, which formed the anterior axillary fold. To our knowledge, this variation has not been previously described. Innervation and vascular supply of this accessory head was from the musculocutaneous nerve and the brachial artery, respectively.

5-Fluorouracil encapsulated alginate beads for the treatment of breast cancer

Alginate beads containing 5-fluorouracil (5-FU) were prepared by the gelation of alginate with calcium cations. Alginate beads loaded with 5-FU were prepared at 1.0 and 2.0% (w/v) polymers. The effect of polymer concentration and the drug loading (1.0, 5.0 and 10%) on the release profile of 5-FU was investigated. As the drug load increased, larger beads were obtained in which the resultant beads contained higher 5-FU content. The encapsulation efficiencies obtained for 5-FU loads of 1.0, 5.0 and 10% (w/v) were 3.5, 7.4 and 10%, respectively. Scanning electron microscopy (SEM) and particle size analysis revealed differences between the formulations as to their appearance and size distribution. The amount of 5-FU released from the alginate beads increased with decreasing alginate concentrations.

Histopathologic Effects of Mitomycin-C on Endoscopic Transnasal Dacryocystorhinostomy

BACKGROUND AND OBJECTIVES The antimetabolite mitomycin-C is now being used in endoscopic transnasal dacryocystorhinostomies to prevent the closure of osteotomies. PATIENTS AND METHODS A 0.5-mg/ml solution of mitomycin-C was applied to the osteotomy site for 2 1/2 minutes intraoperatively. Specimens from four patients were collected during surgery and at 15 days, 1 months, 3 months, and 6 months after surgery. The specimens were examined under light and electron transmission microscopy and were compared with control specimens. RESULTS Light microscopy showed attenuated epithelium with intracytoplasmic vacuoles. Subepithelial connective tissue was looser and hypocellular. Electron microscopy confirmed these findings and demonstrated swelling of mitochondria, dilatation of endoplasmic reticulum, and chromatin-dense granules in nuclei of fibroblasts. CONCLUSION By causing a decrease in density and cellularity of mucosa, topical use of mitomycin-C may enhance the success of surgery; however, further studies are necessary to determine the ultimate potential of this agent for this procedure.

Ultrastructural evaluation of pulsed radiofrequency and conventional radiofrequency lesions in rat sciatic nerve

BACKGROUND PRF treatment has recently been described as minimally neurodestructive alternative to radiofrequency heat lesions. Patients with some pain syndromes in whom the pain could not be controlled by alternative techniques may be treated using PRF. In the present study, our main goal was to evaluate and compare the ultrastructure of peripheral nerve tissue that was heated by PRF, CRF with 42 degrees C, and CRF with 70 degrees C. METHODS Forty-five male rats were divided into 5 groups. In PRF group and CRF with 42 degrees C group, the sciatic nerve was heated at a temperature of 42 degrees C for 120 seconds. As a positive control, some rat sciatic nerves were treated with CRF lesions at 70 degrees C. The rats were kept alive for 21 days and then killed. Tissue was evaluated with transmission electron microscope, and grading was done to the groups. RESULTS The unmyelinated nerve fibers were ultrastructurally normal in all groups. The results of myelinated axons indicated that PRF group had better grades, and CRF with 70 degrees C group had the worst grade. Especially, comparison of the group of PRF and CRF with 42 degrees C revealed significant difference. In PRF group, none of the myelinated axons showed severe degeneration findings, and most of the damaged myelinated axons showed only separation in myelin configuration. CONCLUSIONS PRF treatment may cause separation in myelinated axons. However, it seems that all changes were reversible. The present study supports the hypothesis that pulsed RF treatment does not rely on thermal injury of neurologic tissue to achieve its effect.

Discoid Meniscus An Ultrastructural Study With Transmission Electron Microscopy

Background The ultrastructure of the normal menisci has been thoroughly investigated and found to correlate with meniscal tears. Although discoid menisci are accepted to have the same composition as their normal counterparts, to our knowledge, no study in the literature has investigated this issue. Purpose To investigate the ultrastructure of the discoid menisci and compare it with nondiscoid menisci. Study Design Descriptive laboratory study. Methods Meniscal biopsies were taken from 12 patients who were operated for meniscus tear and diagnosed with discoid meniscus and from 6 patients who were operated for meniscal tear and did not have a diagnosis of discoid meniscus. The samples were examined with transmission electron microscopy. Results The study group demonstrated a decrease in the number of collagen fibers compared with the control group. Also, the homogeneous course of the collagen fibers observed in the control group was replaced by a heterogeneous course in the study group. Conclusion The ultrastructure of the discoid meniscus is different from the normal menisci. Clinical Relevance This difference may contribute to the vulnerability of the discoid meniscus to tears.

Double superior gemellus together with double piriformis and high division of the sciatic nerve

We report a case with double superior gemellus and double piriformis mm. associated with the sciatic n. dividing high and passing between the two piriformis mm. in the same lower extremity. This abnormality has not previously been described in the literature. As many musculoskeletal structures may be involved in sciatica, the supernumerary superior gemelli and piriformis mm. may exert pressure on the sciatic n. and this should be taken into account by clinicians.