Organometallic AlaM Reagents pertaining to Umpolung Peptide Diversification
Bacterial infection has become a crucial reason that give rise to failure of medical implants in clinical applications. RGD peptide molecular weight In this regard, various antibacterial surface modifications of implants have been developed in recent years. However, it remains a challenge to enable the implant surfaces with both suitable antibacterial and osteogenic properties. In this work, ε-polylysine and gum Arabic multilayer composite films were immobilized layer by layer (LBL) on anodized titanium with the assistance of polydopamine for the first time. In vitro antibacterial results showed that the bacteria numbers decreased with an increase in the loading amount of ε-polylysine. Furthermore, long-term antibacterial property up to 3 weeks against both gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli) was obtained combined with the merits of covalent binding and LBL methods. Meanwhile, the cell proliferation and osteogenic differentiation of BMSCs on titanium dioxide nanotubes (TNTs) modified with composite films was significantly improved. Remarkably, a facile method to optimize anti-infective and osteogenic properties of medical titanium has been developed, and it was demonstrated that the ε-polylysine and gum Arabic multilayer composite films with assistance of polydopamine were able to endow the orthopedic implant materials both improved antibacterial property and excellent biocompatibility, which is of profound significance for practical application of titanium-based implants. V.Hydroxyapatite/chitosan (HAp/CS) composites have been widely studied and applied in tissue engineering fields due to their excellent biocompatibility and degradability. However, to improve the mechanical properties of CS, cross-linking agents are commonly added, which will seriously affect its biocompatibility and safety. In this study, the homogenously dispersed nano-hydroxyapatite (nHAp) colloidal solution was first synthesized using a co-precipitation method. The three-dimensional porous nano-hydroxyapatite/chitosan (nHAp/CS) composite scaffolds with different nHAp contents were then obtained through an environmentally friendly freeze-drying process without any cross-linking. The microstructure, porosity, phase composition, swelling ratio, mechanical properties, and biocompatibility of the nHAp/CS scaffolds were thoroughly investigated. The as-prepared nHAp/CS scaffolds exhibited a high porosity and excellent swelling performance. Compared with pure CS scaffolds, the nHAp/CS composite scaffolds not only showed higher compressive modulus but also exhibited better biocompatibility. This study provides a simple and environmentally friendly technique to construct three-dimensional porous nHAp/CS composite scaffolds, which demonstrate promising potential by being a scaffold material for bone tissue engineering. Background/Aims The risk factors for the development of primary biliary cholangitis (PBC) is unclear. This study aimed to investigate the risk factors associated with PBC in Korea through a questionnaire survey. Methods Consecutively enrolled 103 PBC patients from six referral hospitals and 100 age- and sex-matched community controls participated in this study. A standardized questionnaire survey including demographics, lifestyle, individual and familial medical history and reproductive history was prospectively collected and analyzed. Results The PBC patients had a mean age of 58.3 years and a female proportion of 86.4%. The age- and sex-matched controls had a similar educational level and economic status to the PBC patients. Among the lifestyle factors, the multivariable analysis showed smoking including both first-hand and second-hand (odds ratio [OR], 2.03; 95% confidence interval [CI], 1.06 to 3.93), history of autoimmune diseases (OR, 2.46; 95% CI, 1.06 to 6.35), and family history of PBC (OR, 17.76; 95% CI, 1.77 to 2,418.74) were significantly associated with PBC, whereas alcohol intake was negatively associated with PBC. Among reproductive factors, the number of induced abortions was significantly associated with PBC, while the number of full-term deliveries was negatively associated with PBC. Conclusions A family history of PBC, accompanying autoimmune diseases, and smoking were significantly associated with PBC. More induced abortions and less full-term deliveries were associated with PBC in women. In contrast, mild to moderate alcohol intake was negatively associated with PBC. Further studies are warranted to validate the results of this study and to search for clues about the pathogenesis of PBC.Anterior neck burns represent a major reconstructive challenge due to severe sequalae including restriction in movement and poor aesthetic outcomes. Common treatment options include skin grafting with/without dermal matrices, and loco-regional and distant free flap transfers with/without prior tissue expansion. Such variation in technique is largely influenced by the extent of burn injury requiring resurfacing. In order to optimize like-for-like reconstruction of the anterior neck, use of wide, thin and long flaps such as the anterolateral thigh (ALT) perforator flap have been reported with promising results. Of note, some patients have a tendency towards severe scar contractures, which may be contributed by the greater extent of inflammation during wound healing. We report our experience at 4 years' follow-up after secondary reconstruction of severe, anterior neck burn contractures in two patients by harvesting the ALT flap with a butterfly design. This technique provides adequate wound resurfacing of the burned neck and surrounding areas, and provides good neck extensibility by addressing both anterior and lateral aspects of the scar defect simultaneously. Such a flap design reduces tension on wound edges and thus, the risk of contracture recurrence in what remains a particularly challenging type of burn reconstruction.Upper limb nerve damage is a common condition, and evidence suggests that functional recovery may be limited following peripheral nerve repair in cases of delayed reconstruction or reconstruction of long nerve defects. A 26-year-old man presented with traumatic injury from a wide, blunt wound of the right forearm caused by broken glass, with soft tissue loss, complete transection of the radial and ulnar arteries, and a large median nerve gap. The patient underwent debridement and subsequent surgery with a microsurgical free radial fasciocutaneous flap to provide a direct blood supply to the hand; the cephalic vein within the flap was employed as a venous vascularized chamber to wrap the sural nerve graft and to repair the wide gap (14 cm) in the median nerve. During the postoperative period, the patient followed an intensive rehabilitation program and was monitored for functional performance over 5 years of follow-up. Our assessment demonstrated skin tropism and sufficient muscle power to act against strong resistance (M5) in the muscles previously affected by paralysis, as well as a good localization of stimuli in the median nerve region and an imperfect recovery of two-point discrimination (S3+).