Erythrocyte membrane-camouflaged nanoworms with on-demand antibiotic release for eradicating biofilms using near-infrared irradiation

The increase in the number of resistant bacteria caused by the abuse of antibiotics and the emergence of biofilms significantly reduce the effectiveness of antibiotics.Bacterial infections are detrimental to our life and health.To reduce the abuse of antibiotics and treat biofilm-related bacterial infections,a biomimetic nano-antibacterial system,RBCM-NW-G namely,that controls the release of antibiotics through near infrared was prepared.The hollow porous structure and the high surface activity of nanoworms are used to realize antibiotic loading,and then,biomimetics are applied with red blood cell membranes(RBCM).RBCM-NW-G,which retains the performance of RBCM,shows enhanced permeability and retention effects.Fluorescence imaging in mice showed the effective accumulation of RBCM-NW-G at the site of infection.In addition,the biomimetic nanoparticles showed a longer blood circulation time and good biocompatibility.Anti-biofilm test results showed damage to biofilms due to a photothermal effect and a highly efficient antibacterial performance under the synergy of the photothermal effect,silver iron,and antibiotics.Finally,by constructing a mouse infection model,the great potential of RBCM-NW-G in the treatment of in vivo infections was confirmed.

Factors influencing the drug release from calcium phosphate cements

Thanks to their biocompatibility,biodegradability,injectability and self-setting properties,calcium phosphate cements(CPCs)have been the most economical and effective biomaterials of choice for use as bone void fillers.They have also been extensively used as drug delivery carriers owing to their ability to provide for a steady release of various organic molecules aiding the regeneration of defective bone,including primarily antibiotics and growth factors.This review provides a systematic compilation of studies that reported on the controlled release of drugs from CPCs in the last 25 years.The chemical,compositional and microstructural characteristics of these systems through which the control of the release rates and mechanisms could be achieved have been discussed.In doing so,the effects of(i)the chemistry of the matrix,(ii)porosity,(iii)additives,(iv)drug types,(v)drug concentrations,(vi)drug loading methods and(vii)release media have been distinguished and discussed individually.Kinetic specificities of in vivo release of drugs from CPCs have been reviewed,too.Understanding the kinetic and mechanistic correlations between the CPC properties and the drug release is a prerequisite for the design of bone void fillers with drug release profiles precisely tailored to the application area and the clinical picture.The goal of this review has been to shed light on these fundamental correlations.