Multivalent network modifier upregulates bioactivity of multispecies biofilm-resistant polyalkenoate cement

Polyalkenoate cement(PAC)is a promising material for regenerative hard tissue therapy.The ionically rich glass component of PAC encourages bioactive interaction via.the release of essential ions.However,PAC bioactivity is restricted owing to(i)structurally inherent cationic network formers and(ii)surface bacterial biofilm formation.These two factors cause a deficiency in ion release,further complicated by secondary infections and premature therapeutic failure.Here,a multivalent zwitterionic network modifier(mZM)is presented for upregulation of ionic exchange and bioactivity enhancement.By introducing a non-zero charged mZM into PACs,an increase in the proportion of non-bridging oxygen occurs.The network modification promotes ion channel formation,causing a multiple-fold increase in ion release and surface deposition of hydroxy-carbonate apatite(ca.74%).Experiments ex vivo and animal models also demonstrate the efficient remineralization ability of the mZM.Furthermore,divalent cationic interaction results in bacterial biofilm reduction(ca.68%)while also influencing a shift in the biofilm species composition,which favors commensal growth.Therefore,PAC modification with mZM offers a promising solution for upregulation of bioactivity,even aiding in customization by targeting site-specific regenerative therapy in future applications.

Bioresponsive nanotherapy for preventing dental caries by inhibiting multispecies cariogenic biofilms

Early childhood caries(ECC)is a public healthcare concern that greatly reduces the quality of life of young children.As a leading factor of ECC,cariogenic biofilms are composed of acidogenic/aciduric pathogens and extracellular polysaccharides(EPSs),creating an acidic and protected microenvironment.Antimicrobial photodynamic therapy(aPDT)is a noninvasive,painless,and efficient therapeutic approach that is suitable for treating ECC.However,due to the hyperfine structure of cariogenic biofilms,most photosensitizers(PSs)could not access and penetrate deeply in biofilms,which dramatically hamper their efficiency in the clinic.Herein,bioresponsive nanoparticle loaded with chlorin e6(MPP-Ce6)is developed,which largely increases the penetration depth(by over 75%)and retention(by over 100%)of PS in the biofilm compared with free Ce6.Furthermore,MPP-Ce6-mediated aPDT not only kills the bacteria in preformed biofilms but also inhibits multispecies biofilm formation.A rampant caries model is established to mimic ECC in vivo,where the population of cariogenic bacteria is decreased to 10%after MPP-Ce6-mediated aPDT.Importantly,the number and severity of carious lesions are efficiently reduced via Keyes’scoring and micro-CT analysis.This simple but effective strategy can serve as a promising approach for daily oral hygiene in preventing ECC.