Chitosan electrospun nanofibers derived from Periplaneta americana residue for promoting infected wound healing.

Periplaneta americana has been used medicinally for years to treat a wide variety of skin lesions or ulcers. However, a sizable portion of the drug residues that are retained after extraction are routinely thrown away, thus posing a hazard to the environment and depleting resources. In this study, low molecular weight Periplaneta americana chitosan (LPCS) and high molecular weight Periplaneta americana chitosan (HPCS) were extracted from Periplaneta americana residue (PAR) based on the conventional acid-base method and two deacetylation methods. Moreover, the physicochemical properties and structural differences between the above two chitosan and commercial chitosan (CS) were compared using different methods. Next, two nanofibers comprising different ratios of Periplaneta americana chitosan (LPCS or HPCS), polyvinyl alcohol (PVA), and polyethylene oxide (PEO) were prepared and optimized. The above nanofibers exhibited excellent mechanical properties, antibacterial properties, and biocompatibility while facilitating wound healing in an infected rat whole-layer wound model by promoting wound closure, epithelialization, collagen deposition, and inflammation reduction. In brief, this study produced an effective and affordable wound dressing and offered a suggestion for the comprehensive utilization of Periplaneta americana residue.

Extraction and characterization of chitosan from Eupolyphaga sinensis Walker and its application in the preparation of electrospinning nanofiber membranes.

Due to its capabilities for wound healing, antimicrobial defense, hemostasis, and biodegradation, chitosan has seen increased use in biomedical disciplines in recent years. In the meantime, efforts have been made to develop and use insect chitosan as a source to address the seasonal, irritating, and regional shortcomings of traditional shrimp and crab chitosan. In this study, a new type of insect chitosan (DCS) was first extracted from Eupolyphaga sinensis Walker by a low-temperature intermittent method and was compared with commercially available pharmaceutical chitosan (CS). Firstly, the degree of deacetylation and molecular weight of DCS were determined, and DCS was characterized by FT-IR, 1H NMR, XRD, and TGA-DTG. On this basis, DCS was mixed with PVA and PEO to create a novel electrospun nanofiber membrane. The air permeability, antibacterial properties, and biocompatibility of the nanofiber membrane were evaluated, as well as the membrane's shape, structure, and mechanical characteristics. Finally, the activity of nanofiber membranes in promoting wound healing was verified with a rat full-thickness skin defect model, hoping to provide a reference for the development of new drug delivery carriers and wound dressings.

[Studies of electromyography and genetics in children with Charcot-Marie-Tooth disease type 1].

OBJECTIVE: To study the electromyographic and genetic characteristics in children with Charcot-Marie-Tooth disease type 1 (CMT1). METHODS: Routine electromyography and nerve conduction were performed in 24 children with CMT1. Polymerase chain reaction (PCR) combined with restriction enzyme digestion was used to detect gene duplication on chromosome 17p11.2-12. Ten healthy children served as the control group. RESULTS: The peripheral nerve conduction velocity slowed or disappeared in all of the 24 patients (100%). The lesions of the sensory nerves were more severe than the motor nerves, and the lesions of the lower limbs were more severe than the upper limbs. Of 72 muscles detected, 40 (56%) showed neurogenic lesions. The older the patients, the more severe the muscle lesions. Specific junction fragments (1760 bp) were identified in 13 (54%) out of 24 patients, but were not identified in the healthy controls. CONCLUSIONS: The electromyographic changes are characterized by peripheral nerve conduction velocities slowing and neurogenic lesions of muscles in children with CMT1. The PCR combined with restriction enzyme digestion may be a simple and accurate method for gene diagnosis of CMT1.

Treatment of serologically negative Sjögren's syndrome with tacrolimus: A case report.

We herein report an unusual case of primary Sjögren's syndrome in a 38-year-old woman with typical clinical symptoms (joint pain, dry mouth, and positive Schirmer test) and immunoglobulin G positivity but negativity for antinuclear antibody and all antinuclear antibody spectrum antibodies. Emission computed tomography demonstrated normal ingestion but impaired secretion by the submandibular and bilateral parotid glands. Labial gland biopsy revealed chronic tissue inflammatory changes and Chisholm grade 4 lymphocyte infiltration, confirming primary Sjögren's syndrome. The patient's condition was successfully controlled by nonsteroidal treatment with tacrolimus. Patients presenting with chronic dry mouth should be examined by a Schirmer test, lip gland biopsy, and salivary gland emission computed tomography for possible Sjögren's syndrome, even if serological autoantibodies are negative, to facilitate early intervention. Tacrolimus is a potential treatment option in patients intolerant of steroidal drugs.

Codelivery of doxorubicin and elacridar to target both liver cancer cells and stem cells by polylactide-co-glycolide/d-alpha-tocopherol polyethylene glycol 1000 succinate nanoparticles.

PURPOSE: Liver cancer is the third leading cause of cancer-related deaths worldwide. Liver cancer stem cells (LCSCs) are a subpopulation of cancer cells that are responsible for the initiation, progression, drug resistance, recurrence, and metastasis of liver cancer. Recent studies have suggested that the eradication of both LCSCs and liver cancer cells is necessary because the conversion of cancer stem cells (CSCs) to cancer cells occasionally occurs. As ATP-binding cassette (ABC) transporters are overexpressed in both CSCs and cancer cells, combined therapies using ABC transporter inhibitors and chemotherapy drugs could show superior therapeutic efficacy in liver cancer. In this study, we developed poly(lactide-co-glycolide)/d-alpha-tocopherol polyethylene glycol 1000 succinate nanoparticles to accomplish the simultaneous delivery of an optimized ratio of doxorubicin (DOX) and elacridar (ELC) to target both LCSCs and liver cancer cells. METHODS: Median-effect analysis was used for screening of DOX and ELC for synergy in liver cancer cells (HepG2 cells) and LCSCs (HepG2 tumor sphere [HepG2-TS]). Then, nanoparticles loaded with DOX and ELC at the optimized ratio (NDEs) were prepared by nanoprecipitation method. The cytotoxicity and colony and tumor sphere formation ability of nanoparticles were investigated in vitro, and the tissue distribution and antitumor activity of nanoparticles were evaluated in vivo. RESULTS: We demonstrated that a DOX/ELC molar ratio of 1:1 was synergistic in HepG2 cells and HepG2-TS. NDEs were shown to exhibit significantly increased cytotoxic effects against both HepG2 and HepG2-TS compared with DOX-loaded nanoparticles (NDs) or ELC-loaded nanoparticles (NEs) in vitro. In vivo studies demonstrated that the nanoparticles exhibited better tumor targeting, with NDE showing the strongest antitumor activity with lower systemic toxicity. CONCLUSION: These results suggested that NDE represented a promising combination therapy against liver cancer by targeting both liver cancer cells and CSCs.