Ultrasound-triggered piezocatalytic composite hydrogels for promoting bacterial-infected wound healing

Wound healing has become one of the basic issues faced by the medical community because of the susceptibility of skin wounds to bacterial infection.As such,it is highly desired to design a nanocomposite hydrogel with excellent antibacterial activity to achieve high wound closure effectiveness.Here,based on ultrasound-triggered piezocatalytic therapy,a multifunctional hydrogel is designed to promote bacteria-infected wound healing.Under ultrasonic vibration,the surface of barium titanate(BaTiO_(3),BT)nanoparticles embedded in the hydrogel rapidly generate reactive oxygen species(ROS)owing to the established strong built-in electric field,endowing the hydrogel with superior antibacterial efficacy.This modality shows intriguing advantages over conventional photodynamic therapy,such as prominent soft tissue penetration ability and the avoidance of serious skin phototoxicity after systemic administration of photosensitizers.Moreover,the hydrogel based on N-[tris(hydroxymethyl)methyl]acrylamide(THM),N-(3-aminopropyl)methacrylamide hydrochloride(APMH)and oxidized hyaluronic acid(OHA)exhibits outstanding self-healing and bioadhesive properties able to accelerate full-thickness skin wound healing.Notably,compared with the widely reported mussel-inspired adhesive hydrogels,OHA/THM-APMH hydrogel due to the multiple hydrogen bonds from unique tri-hydroxyl structure overcomes the shortage that catechol groups are easily oxidized,giving it long-term and repeatable adhesion performance.Importantly,this hybrid hydrogel confines BT nanoparticles to wound area and locally induced piezoelectric catalysis under ultrasound to eradicate bacteria,markedly improving the therapeutic biosafety and exhibits great potential for harmless treatment of bacteria-infected tissues.

Curve evolution during bracing in children with scoliosis secondary to early-onset neurofibromatosis type 1:indicators of rapid curve progression

Background:Scoliosis secondary to neurofibromatosis type 1(NF1)in children aged<10 years is an important etiology of earlyonset scoliosis(EOS).This study was performed to investigate the curve evolution of patients with EOS secondary to NF1 undergoing bracing treatment and to analyze high-risk indicators of rapid curve progression.Methods:Children with EOS due to NF1 who underwent bracing treatment from 2010 to 2017 were retrospectively reviewed.The angle velocity(AV)at each visit was calculated,and patients with rapid curve progression(AV of>10°/year)were identified.The age at modulation and the AV before and after modulation were obtained.Patients with(n=18)and without rapid curve progression(n=10)were statistically compared.Results:Twenty-eight patients with a mean age of 6.5±1.9 years at the initial visit were reviewed.The mean Cobb angle of the main curve was 41.7°±2.4°at the initial visit and increased to 67.1°±8.6°during a mean follow-up of 44.1±8.5 months.The overall AV was 6.6°±2.4°/year for all patients.At the last follow-up,all patients presented curve progression of>5°,and 20(71%)patients had progressed by>20°.Rapid curve progression was observed in 18(64%)patients and was associated with younger age at the initial visit and a higher incidence of modulation change during follow-up(t=2.868,P=0.008 and<0.001,respectively).The mean AV was 4.4°±1.2°/year before modulation and 11.8°±2.7°/year after modulation(t=11.477,P<0.010).Conclusions:Curve progression of>10°/year is associated with younger age at the initial visit,and modulation change indicated the occurrence of the rapid curve progression phase.