Environment-responsive drug delivery systems for targeted cancer therapy

In order to deliver and/or release anti-cancer therapeutics at the tumor sites, novel environment-responsive drug delivery systems are designed to specifically respond to tumor microenvironment （such as low pH and hypoxia）. Due to their extraordinary advantages, these environment-responsive drug delivery systems can improve antitumor efficacy, and most importantly, they can decrease toxicity associated with the anti-cancer therapeutics. This review highlights different mechanisms of environmentresponsive drug delivery systems and their applications for targeted cancer therapy.

Mapping multiple phases in curcumin binary solid dispersions by fluorescence contrasting

The microphases and miscibility in binary curcumin(Cur)solid dispersions(SDs)with amorphous polyvinylpyrrolidone K30(PVP K30)and semi-crystalline poloxamer(P407)and poly(ethylene glycol)6000(PEG6000)as carriers were investigated by fluorescence contrasting utilizing confocal laser scanning microscopy.A super sensitive fluorophore P4 with typical aggregation-caused quenching properties was employed to stain the continuous polymer phases and contrasted with the autofluorescence of the model drug Cur.In addition,differential scanning calorimetry(DSC)and powder X-ray diffraction(PXRD)were utilized to assist in explanation of the fluorescence results.In all three SD systems,there is always a homogenous polymer phase stained by P4 and it is difficult to adulterate Cur crystals by P4.Cur-enriched rather than polymer-enriched domains could be detected.In the Cur-PVP K30 system,Cur exists in an amorphous form at a Cur loading level of 50%and below,while Cur crystallines phase out and continuously grow with the increase of Cur loading from 60%to 90%.The phase behaviors in the Cur-P407 and Cur-PEG 6000 systems are similar but with minor differences.In both systems,Cur phases out as clusters of drug-enriched domains at a loading level of 20%and below,which however cannot be correlated with crystallization,as evidenced by both DSC and PXRD.There is a transition from an amorphous to a crystalline state from 20%to 30%Cur loading,above which Cur crystallines can be detected.It is interesting that a co-mix phase of both Cur-and PEG 6000-enriched domains can be identified at Cur loading levels of 10%and less.Taking together,it is concluded that contrasting Cur autofluorescence with the signals of P4 proves to be a functional strategy to reveal multiple phases in the binary SD systems investigated.

Targeted nanomedicines remodeling immunosuppressive tumor microenvironment for enhanced cancer immunotherapy

Cancer immunotherapy has significantly flourished and revolutionized the limited conventional tumor therapies,on account of its good safety and long-term memory ability.Discouragingly,low patient response rates and potential immune-related side effects make it rather challenging to literally bring immunotherapy from bench to bedside.However,it has become evident that,although the immunosuppressive tumor microenvironment(TME)plays a pivotal role in facilitating tumor progression and metastasis,it also provides various potential targets for remodeling the immunosuppressive TME,which can consequently bolster the effectiveness of antitumor response and tumor suppression.Additionally,the particular characteristics of TME,in turn,can be exploited as avenues for designing diverse precise targeting nanomedicines.In general,it is of urgent necessity to deliver nanomedicines for remodeling the immunosuppressive TME,thus improving the therapeutic outcomes and clinical translation prospects of immunotherapy.Herein,we will illustrate several formation mechanisms of immunosuppressive TME.More importantly,a variety of strategies concerning remodeling immunosuppressive TME and strengthening patients'immune systems,will be reviewed.Ultimately,we will discuss the existing obstacles and future perspectives in the development of antitumor immunotherapy.Hopefully,the thriving bloom of immunotherapy will bring vibrancy to further exploration of comprehensive cancer treatment.

Discriminating against injectable fat emulsions with similar formulation based on water quenching fluorescent probe

The discrimination against nutritional fat emulsion injections was considered by imaging tools,which aims to elucidate the in vivo behaviors of nanoemulsions.In this study,20%nutritional fat emulsion injections were selected from different company including original and generic products.Meanwhile,a water quenching fluorescent probe(P2)was used to label them by an incubation method.The fluorescent intensity analysis of blood-borne fluorescence reveals rapid clearance of nanoemulsion in all groups,which shows'L'-type blood kinetic profiles.However,these kinetic parameters do not have significant difference.Following intravenous administration,the nanoemulsions in all groups concomitantly accumulated in organs of reticulo-endothelial system(RES),such as liver and spleen,and were cleared from body circulation mostly after 12 h.AUC(0-t)of organs from different groups showed dissimilar results in some organs.These intuitional results are of significance in understa nding the in vivo behaviors of nanoemulsions,which can provide a new way to discriminate against nutritional fat emulsions.