A review of current advancements for wound healing: Biomaterial applications and medical devices.

Wound healing is a complex process that is critical in restoring the skin's barrier function. This process can be interrupted by numerous diseases resulting in chronic wounds that represent a major medical burden. Such wounds fail to follow the stages of healing and are often complicated by a pro-inflammatory milieu attributed to increased proteinases, hypoxia, and bacterial accumulation. The comprehensive treatment of chronic wounds is still regarded as a significant unmet medical need due to the complex symptoms caused by the metabolic disorder of the wound microenvironment. As a result, several advanced medical devices, such as wound dressings, wearable wound monitors, negative pressure wound therapy devices, and surgical sutures, have been developed to correct the chronic wound environment and achieve skin tissue regeneration. Most medical devices encompass a wide range of products containing natural (e.g., chitosan, keratin, casein, collagen, hyaluronic acid, alginate, and silk fibroin) and synthetic (e.g., polyvinyl alcohol, polyethylene glycol, poly[lactic-co-glycolic acid], polycaprolactone, polylactic acid) polymers, as well as bioactive molecules (e.g., chemical drugs, silver, growth factors, stem cells, and plant compounds). This review addresses these medical devices with a focus on biomaterials and applications, aiming to deliver a critical theoretical reference for further research on chronic wound healing.

Engineering and polymeric composition of drug-eluting suture: A review.

Sutures are the most popular surgical implants in the global surgical equipment market. They are used for holding tissues together to achieve wound closure. However, controlling the body's immune response to these "foreign bodies" at site of infection is challenging. Natural polymers such as collagen, silk, nylon, and cotton, and synthetic polymers such as polycaprolactone, poly(lactic-co-glycolic acid), poly(p-dioxanone) and so forth, contribute the robust foundation for the engineering of drug-eluting sutures. The incorporation of active pharmaceutical ingredients (APIs) with polymeric composition of suture materials is an efficient way to reduce inflammatory reaction in the wound site as well as to control bacterial growth, while allowing wound healing. The incorporation of polymeric composition in surgical sutures has been found to add high flexibility as well as excellent physical and mechanical properties. Fabrication processes and polymer materials allow control over drug-eluting profiles to effectively address wound healing requirements. This review outlines and discusses (a) polymer materials and APIs used in suture applications, including absorbable and nonabsorbable sutures; (b) suture structures, such as monofilament, multifilament, barded and smart sutures; and (c) the existing manufacturing techniques for drug-eluting suture production, including electrospinning, melt-extrusion and coating.

Fabrication and characterisation of melt-extruded chitosan/keratin/PCL/PEG drug-eluting sutures designed for wound healing.

Diclofenac potassium loaded sutures based upon PEG/PCL/chitosan-keratin blends were fabricated using the hot-melt extrusion technique. Polymer sutures were evaluated based on their physical, thermal and mechanical properties, while the drug-eluting sutures were evaluated for drug release properties. Lastly, the performance of the drug-loaded sutures in the contact with the human keratinocyte cell line HaCat were assessed. Results showed that the sutures extruded homogeneously at a temperature of 63 ± 1 °C providing a uniform thickness of fibres. Analysis by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) showed that completely amorphous and miscible solid dispersions were created. Fourier transform infrared (FTIR) spectroscopy indicated that the presence of hydrogen bonds between the polymers improved material miscibility. Tensile properties of the sutures were clearly affected by the PEG, chitosan and keratin additions. The optimal formulation of tensile strength was obtained when PCL/PEG/chitosan-keratin were combined at a ratio of 80/19/1 w/w. Rapid and sustained drug release rates were achieved with the PEG/PCL/chitosan/keratin blends at various combinations. The composite of PCL/PEG/chitosan-keratin with 30 wt% of diclofenac potassium also exhibited high cell viability and wound healing rates in vitro cytotoxicity testing. The anti-inflammatory properties imparted by the PCL/PEG/chitosan/keratin/drug sutures may further the use of composite sutures for wound healing in clinical settings.

A novel P755L mutation in LRRK2 gene associated with Parkinson's disease.

Parkinson's disease is a common neurodegenerative disorder. The identification of leucine-rich repeat kinase 2 (LRRK2) gene mutations as a cause of Parkinson's disease has greatly expanded our knowledge of the genetic and molecular pathogenesis of this disorder. By denaturing high-performance liquid chromatography and gene sequencing in patients and controls, we identified a novel frequent heterozygous 2264C-->T substitution, which causes a proline-to-leucine mutation (P755L) in LRRK2 gene. In our sample of 598 patients of Chinese Han ancestry, 12 cases carried the same LRRK2 mutation. Our results indicated that this single mutation was implicated in 2% of sporadic patients. We suggest that testing for this mutation will be important in the management and genetic counseling of patients with Parkinson's disease.

Prenatal diagnosis of spinal muscular atrophy in Chinese by genetic analysis of fetal cells.

BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by degeneration of anterior horn cells of the spinal cord. The survival motor neuron gene is SMA-determining gene deleted in approximately 95% of SMA patients. This study was undertaken to predict prenatal SMA efficiently and rapidly in families with previously affected child. METHODS: Prenatal diagnosis was made in 8 fetuses with a family history of SMA. Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were used for the detection of the survival motor neuron gene. RESULTS: The survival motor neuron gene was not found in 6 fetuses, ruling out the diagnosis of SMA. Two fetuses were detected positive and the pregnancies were terminated. CONCLUSION: Our method is effective and convenient in prenatal diagnosis of SMA.