Arman Zaharil Mat Saad

Wound Bed Preparation for Chronic Diabetic Foot Ulcers

The escalating incidence of diabetic mellitus has given rise to the increasing problems of chronic diabetic ulcers that confront the practice of medicine. Peripheral vascular disease, neuropathy, and infection contribute to the multifactorial pathogenesis of diabetic ulcers. Approaches to the management of diabetic ulcers should start with an assessment and optimization of the patients general conditions, followed by considerations of the local and regional factors. This paper aims to address the management strategies for wound bed preparation in chronic diabetic foot ulcers and also emphasizes the importance of preventive measures and future directions. The “TIME” framework in wound bed preparation encompasses tissue management, inflammation and infection control, moisture balance, and epithelial (edge) advancement. Tissue management aims to remove the necrotic tissue burden via various methods of debridement. Infection and inflammation control restores bacterial balance with the reduction of bacterial biofilms. Achieving a moist wound healing environment without excessive wound moisture or dryness will result in moisture balance. Epithelial advancement is promoted via removing the physical and biochemical barriers for migration of epithelium from wound edges. These systematic and holistic approaches will potentiate the healing abilities of the chronic diabetic ulcers, including those that are recalcitrant.

In vitro capacity of different grades of chitosan derivatives to induce platelet adhesion and aggregation

Chitosan-derived hemostatic agents with various formulations may have distinct potential in hemostasis. This study assessed the ability of different grades and forms of chitosan derivatives as hemostatic agents to enhance platelet adhesion and aggregation in vitro. The chitosan derivatives utilized were 2% NO-CMC, 7% NO-CMC (with 0.45 mL collagen), 8% NO-CMC, O-C 52, 5% O-CMC-47, NO-CMC-35, and O-C 53. Samples of chitosan derivatives weighing 5mg were incubated at 37°C with 50 μL of phosphate buffer saline (PBS) (pH 7.4) for 60 min. The morphological features of the platelets upon adherence to the chitosan were viewed using scanning electron microscope (SEM), and the platelet count was analyzed with an Automated Hematology Analyzer. For platelet aggregation, we added an adenosine diphosphate (ADP) agonist to induce the chitosan-adhered platelets. O-C 52 bound with platelets exhibited platelet aggregates and clumps on the surface of the membrane layer with approximately 70-80% coverage. A statistically significant correlation (p<0.01) for the platelet count was identified between the baseline value and the values at 10 min and 20 min. The results indicate that O-C 53 and O-C 52 were able to promote clotting have the potential to induce the release of platelets engaged in the process of hemostasis.

Evaluation of the Biocompatibility of a Bilayer Chitosan Skin Regenerating Template, Human Skin Allograft, and Integra Implants in Rats

Introduction. Chitosan is a nontoxic, biocompatible, and biodegradable polymer obtained from chitin by N-deacetylation using strong alkali. Chitosan in a form of a bilayer skin regenerating template can act as a scaffold for regeneration. Integra is a two-layer skin regeneration system, constructed of a matrix of crosslinked fibers that acts as a scaffold for regenerating dermal skin cells. Human skin allografts (HSAs) are the “gold standard” for temporary coverage of clean burn wounds. Objectives. The objective of this study was to conduct in-vivo, preclinical biocompatibility evaluations of Integra, HSA, and Chitosan skin regenerating template (SRT). Methods. Paravertebral subcutaneous pockets were created for the implantation of test materials. Implants were retrieved after 4, 7, 14, 21, and 28 days. Slides of sections through the implants were examined to determine biocompatibility. Results. Chitosan SRT and Integra showed similar inflammatory patterns. HSA showed a higher inflammatory reaction initially which then reduced to levels similar to Integra and Chitosan SRT. Chitosan SRT and Integra also shared similar angiogenesis levels. Towards the end, all implants were degraded with decreased tissue response. Conclusion. Integra, Chitosan SRT, and HSA have been shown to be biocompatible. Integra and Chitosan SRT seem to illicit similar tissue responses.

Prognostic factors and survival rate of osteosarcoma: A single-institution study

Osteosarcoma is a highly malignant primary bone tumor. The study aim to evaluate the prognostic factors influencing the survival rate in our center.

Chitosan: A promising marine polysaccharide for biomedical research

Biomaterials created 50 years ago are still receiving considerable attention for their potential to support development in the biomedical field. Diverse naturally obtained polysaccharides supply a broad range of resources applicable in the biomedical field. Lately, chitosan, a marine polysaccharide derived from chitins—which are extracted from the shells of arthropods such as crab, shrimp, and lobster—is becoming the most wanted biopolymer for use toward therapeutic interventions. This is a general short review of chitosan, highlighting the history, properties, chemical structure, processing method, and factors influencing the usage of chitosan derivatives in the biomedical field.

Long-term outcome of free fibula osteocutaneous flap and massive allograft in the reconstruction of long bone defect

Reconstruction of massive bone defects in bone tumors with allografts has been shown to have significant complications including infection, delayed or nonunion of allograft, and allograft fracture. Resection compounded with soft tissue defects requires skin coverage. A composite osteocutaneous free fibula offers an optimal solution where the allografts can be augmented mechanically and achieve biological incorporation. Following resection, the cutaneous component of the free osteocutaneous fibula flaps covers the massive soft tissue defect. In this retrospective study, the long-term outcome of 12 patients, who underwent single-stage limb reconstruction with massive allograft and free fibula osteocutaneous flaps instead of free fibula osteal flaps only, was evaluated. This study included 12 consecutive patients who had primary bone tumors and had follow-up for a minimum of 24 months. The mean age at the time of surgery was 19.8 years. A total of eight patients had primary malignant bone tumors (five osteosarcomas, two chondrosarcomas and one synovial sarcoma), and four patients had benign bone tumors (two giant-cell tumors, one aneurysmal bone cyst, and one neurofibromatosis). The mean follow-up for the 12 patients was 63 months (range 24-124 months). Out of the 10 patients, nine underwent lower-limb reconstruction and ambulated with partial weight bearing and full weight bearing at an average of 4.2 months and 8.2 months, respectively. In conclusion, augmentation of a massive allograft with free fibula osteocutaneous flap is an excellent alternative for reducing the long-term complication of massive allograft and concurrently addresses the soft tissue coverage.

Glycoprotein IIb/IIIa and P2Y12 Induction by Oligochitosan Accelerates Platelet Aggregation

Platelet membrane receptor glycoprotein IIb/IIIa (gpiibiiia) is a receptor detected on platelets. Adenosine diphosphate (ADP) activates gpiibiiia and P2Y12, causing platelet aggregation and thrombus stabilization during blood loss. Chitosan biomaterials were found to promote surface induced hemostasis and were capable of activating blood coagulation cascades by enhancing platelet aggregation. Our current findings show that the activation of the gpiibiiia complex and the major ADP receptor P2Y12 is required for platelet aggregation to reach hemostasis following the adherence of various concentrations of chitosan biomaterials [7% N,O-carboxymethylchitosan (NO-CMC) with 0.45 mL collagen, 8% NO-CMC, oligochitosan (O-C), and oligochitosan 53 (O-C 53)]. We studied gpiibiiia and P2Y12 through flow cytometric analysis and western blotting techniques. The highest expression of gpiibiiia was observed with Lyostypt (74.3 ± 7.82%), followed by O-C (65.5 ± 7.17%). Lyostypt and O-C resulted in gpiibiiia expression increases of 29.2% and 13.9%, respectively, compared with blood alone. Western blot analysis revealed that only O-C 53 upregulated the expression of P2Y12 (1.12 ± 0.03-fold) compared with blood alone. Our findings suggest that the regulation of gpiibiiia and P2Y12 levels could be clinically useful to activate platelets to reach hemostasis. Further, we show that the novel oligochitosan is able to induce the increased expression of gpiibiiia and P2Y12, thus accelerating platelet aggregation in vitro.

The use of glycerol-preserved skin allograft in conjunction with reconstructive and flap surgery: seven years of experience.

Major reconstructive surgery may be extensive and prolonged, and it may cause edema and compromise the flap pedicle if closed under tension. Glycerol-preserved skin allograft (GPA) can provide a means for tension-free closure and temporary cover of the wound. Seven years of analysis on GPA used in conjunction with major reconstruction was undertaken to highlight its indications, results, and outcomes. Forty-seven patients were included, aged between 9 and 73 years. Majority of patients had reconstruction following tumor resection and trauma. The main indication for use of GPA was temporary, loose cover of the wound in 44% of cases; flap pedicle protection in 31% of cases; donor site wound cover in 10%; flap monitoring in one case; and management of flap-related complications in 6% of cases. Free flap reconstruction was performed in 72% of cases. In conclusion, GPA is a useful adjunct in reconstructive surgery. It can be used temporarily to allow tension-free wound closure, as well as to protect the flap pedicle until edema subsides and the pedicle becomes stable. This latter approach allows secondary wound closure and good esthetic outcome.

Amniotic Membrane in the Treatment of Burns

Burn wound dressing represents an important aspect of burn care. The various inherent features of amniotic membrane proved to be useful as it contributes towards the attributes of an ideal dressing. This biological dressing is inexpensive, able to enhance re-epithelialization, readily available and stored, hence rendering it suitable for a wide range of burn wound treatment. The different preparations of amniotic membrane provide additional benefit whereby clinicians can have a range of product to choose from. Pain relief, good wound adherence and conformability further increase the importance of amnion as burn wound dressing. The versatility and efficacy of the amnion makes it an attractive option despite of the enormous range commercially available wound management products in the market. This chapter presents a review of the various aspects of amniotic membrane for burn wound treatment.

Successful pregnancy "during" pedicled transverse rectus abdominis musculocutaneous flap for breast reconstruction with normal vaginal delivery

A transverse rectus abdominis myocutaneous (TRAM) flap is a popular choice for breast reconstruction. Pregnancies in women following a TRAM flap present concerns regarding both safety and the integrity of the abdominal wall. We report a case of a patient who was pregnant during immediate breast reconstruction with pedicled TRAM flap and had a successful spontaneous vaginal delivery. We also conducted a literature review using PubMed on pregnancy post TRAM flap, type of reconstruction, timing of pregnancy after TRAM flap, complication, and mode of delivery, which are summarised in this report. We concluded that patients may have safe pregnancies and normal deliveries following TRAM flap breast reconstruction regardless of the time frame of pregnancy after the procedure. Therefore, TRAM flaps can continue to be a reconstruction option, even in women of childbearing age.