Construction of a 980 nm laser-activated Pt(Ⅱ)metallacycle nanosystem for efficient and safe photo-induced bacteria sterilization

Although metal-based chemical agents have demonstrated promising bacteriostatic effects in phototherapy,their short excitation/emission wavelengths and inadequate phototherapy efficiencies make their application in vivo difficult.We therefore synthesized a novel Pt(Ⅱ)metallacycle(Pt1110)that can be activated with a 980 nm laser for photodiagnosis/treatment in deep tissue.We found that Pt1110 significantly improved photothermal conversion(95%improvement)and ^(1)O_(2) generation(ΦΔ75%increase)compared to the ligand itself 1 and was well capable of light-induced sterilization under safe laser irradiation(0.72 W/cm^(2)).In addition,Pt1110 has little to no toxicity to cells.After incorporated into liposome,Pt1110 NPs was effective in wound healing in infection and keratitis models upon laser irradiation,which was accurately observed by NIR-Ⅱfluorescence imaging.This novel metal-coordinated supramolecular material has a potential to become a universal platform for phototherapy in deep tissue.

Regulating the microenvironment with nanomaterials:Potential strategies to ameliorate COVID-19

COVID-19,caused by SARS-CoV-2,has resulted in serious economic and health burdens.Current treatments remain inadequate to extinguish the epidemic,and efficient therapeutic approaches for COVID-19 are urgently being sought.Interestingly,accumulating evidence suggests that microenvironmental disorder plays an important role in the progression of COVID-19 in patients.In addition,recent advances in nanomaterial technologies provide promising opportunities for alleviating the altered homeostasis induced by a viral infection,providing new insight into COVID-19 treatment.Most literature reviews focus only on certain aspects of microenvironment alterations and fail to provide a comprehensive overview of the changes in homeostasis in COVID-19 patients.To fill this gap,this review systematically discusses alterations of homeostasis in COVID-19 patients and potential mechanisms.Next,advances in nanotechnology-based strategies for promoting homeostasis restoration are summarized.Finally,we discuss the challenges and prospects of using nanomaterials for COVID-19 management.This review provides a new strategy and insights into treating COVID-19 and other diseases associated with microenvironment disorders.

Picomolar-sensitiveβ-amyloid fibril fluorophores by tailoring the hydrophobicity of biannulatedπ-elongated dioxaborine-dyes

The pathological origin of Alzheimer’s disease(AD)is still shrouded in mystery,despite intensive worldwide research efforts.The selective visualization ofβ-amyloid(Aβ),the most abundant proteinaceous deposit in AD,is pivotal to reveal AD pathology.To date,several small-molecule fluorophores for Aβspecies have been developed,with increasing binding affinities.In the current work,two organic small-molecule dioxaborine-derived fluorophores were rationally designed through tailoring the hydrophobicity with the aim to enhance the binding affinity for Aβ_(1-42) fibrils-while concurrently preventing poor aqueous solubility-via biannulate donor motifs in D-π-A dyes.An unprecedented sub-nanomolar affinity was found(K_(d)=0.62±0.33 nM)and applied to super-sensitive and red-emissive fluorescent staining of amyloid plaques in cortical brain tissue ex vivo.These fluorophores expand the dioxaborine-curcumin-based family of Aβ-sensitive fluorophores with a promising new imaging agent.

2D-ultrathin MXene/DOXjade platform for iron chelation chemo-photothermal therapy

An increased demand for iron is a hallmark of cancer cells and is thought necessary to promote high cell proliferation,tumor progression and metastasis.This makes iron metabolism an attractive therapeutic target.Unfortunately,current iron-based therapeutic strategies often lack effectiveness and can elicit off-target toxicities.We report here a dual-therapeutic prodrug,DOXjade,that allows for iron chelation chemo-photothermal cancer therapy.This prodrug takes advantage of the clinically approved iron chelator deferasirox(ExJade®)and the topoisomerase 2 inhibitor,doxorubicin(DOX).Loading DOXjade onto ultrathin 2D Ti_(3)C_(2) MXene nanosheets produces a construct,Ti_(3)C_(2)-PVP@DOXjade,that allows the iron chelation and chemotherapeutic functions of DOXjade to be photo-activated at the tumor sites,while potentiating a robust photothermal effect with photothermal conversion efficiencies of up to 40%.Antitumor mechanistic investigations reveal that upon activation,Ti_(3)C_(2)-PVP@DOXjade serves to promote apoptotic cell death and downregulate the iron depletion-induced iron transferrin receptor(TfR).A tumor pH-responsive iron chelation/photothermal/chemotherapy antitumor effect was achieved both in vitro and in vivo.The results of this study highlight what may constitute a promising iron chelation-based phototherapeutic approach to cancer therapy.