A pH-sensitive supramolecular nanosystem with chlorin e6 and triptolide co-delivery for chemo-photodynamic combination therapy

The combination of Ce6,an acknowledged photosensitizer,and TPL,a natural anticancer agent,has been demonstrated as a useful strategy to reinforce the tumor growth suppression,as well as decrease the systemic side effects compared with their monotherapy.However,in view of the optimal chemo-photodynamic combination efficiency,there is still short of the feasible nanovehicle to steadily co-deliver Ce6 and TPL,and stimuli-responsively burst release drugs in tumor site.Herein,we described the synergistic antitumor performance of a pH-sensitive supramolecular nanosystem,mediated by the host–guest complexing betweenβ-CD and acid pH-responsive amphiphilic co-polymer mPEG-PBAE-mPEG,showing the shell–core structural micelles with the tightβ-CD layer coating.Both Ce6 and TPLwere facilely co-loaded into the spherical supramolecular NPs(TPL+Ce6/NPs)by one-step nanoprecipitation method,with an ideal particle size(156.0 nm),acid pH-responsive drug release profile,and enhanced cellular internalization capacity.In view of the combination benefit of photodynamic therapy and chemotherapy,as well as co-encapsulation in the fabricated pH-sensitive supramolecular NPs,TPL+Ce6/NPs exhibited significant efficacy to suppress cellular proliferation,boost ROS level,lower MMP,and promote cellular apoptosis in vitro.Particularly,fluorescence imaging revealed that TPL+Ce6/NPs preferentially accumulated in the tumor tissue area,with higher intensity than that of free Ce6.As expected,upon 650-nm laser irradiation,TPL+Ce6/NPs exhibited a cascade of amplified synergistic chemo-photodynamic therapeutic benefits to suppress tumor progression in both hepatoma H22 tumor-bearingmice and B16 tumor-bearingmice.More importantly,lower systemic toxicitywas found in the tumor-bearingmice treated with TPL+Ce6/NPs.Overall,the designed supramolecular TPL+Ce6/NPs provided a promising alternative approach for chemo-photodynamic therapy in tumor treatment.

pH-activatable oxidative stress amplifying dissolving microneedles for combined chemo-photodynamic therapy of melanoma

Photodynamic therapy(PDT)-mediated oxidation treatment is extremely attractive for skin melanoma ablation,but the strong hydrophobicity and poor tumor selectivity of photosensitizers,as well as the oxygen-consuming properties of PDT,leading to unsatisfactory therapeutic outcomes.Herein,a tumor acidic microenvironment activatable dissolving microneedle(DHA@HPFe-MN)was developed to realize controlled drug release and excellent chemo-photodynamic therapy of melanoma via oxidative stress amplification.The versatile DHA@HPFe-MN was fabricated by crosslinking a self-synthesized protoporphyrin(PpIX)-ADH-hyaluronic acid(HA)conjugate HA-ADH-PpIX with“iron reservoir”PA-Fe 3+complex in the needle tip via acylhydrazone bond formation,and dihydroartemisinin(DHA)was concurrently loaded in the hydrogel network.HA-ADH-PpIX with improved water solubility averted undesired aggregation of PpIX to ensure enhanced PDT effect.DHA@HPFe-MN with sharp needle tip,efficient drug loading and excellent mechanical strength could efficiently inserted into skin and reach the melanoma sites,where the acidic pH triggered the degradation of microneedles,enabling Fe-activated and DHA-mediated oxidation treatment,as evidenced by abundant reactive oxygen species(ROS)generation.Moreover,under light irradiation,a combined chemo-photodynamic therapeutic effect was achieved with amplified ROS generation.Importantly,the Fe-catalyzed ROS production of DHA was oxygen-independent,which work in synergy with the oxygen-dependent PDT to effectively destroy tumor cells.This versatile microneedles with excellent biosafety and biodegradability can be customized as a promising localized drug delivery system for combined chemo-photodynamic therapy of melanoma.

H_(2)O_(2)-responsive polymer prodrug nanoparticles with glutathione scavenger for enhanced chemo-photodynamic synergistic cancer therapy

The combination of chemotherapy and photodynamic therapy(PDT)based on nanoparticles(NPs)has been extensively developed to improve the therapeutic effect and decrease the systemic toxicity of current treatments.However,overexpressed glutathione(GSH)in tumor cells efficiently scavenges singlet oxygens(^(1)O_(2))generated from photosensitizers and results in the unsatisfactory efficacy of PDT.To address this obstacle,here we design H_(2)O_(2)-responsive polymer prodrug NPs with GSH-scavenger(Ce6@P(EG-a-CPBE)NPs)for chemo-photodynamic synergistic cancer therapy.They are constructed by the co-self-assembly of photosensitizer chlorin e6(Ce6)and amphiphilic polymer prodrug P(EG-a-CPBE),which is synthesized from a hydrophilic alternating copolymer P(EG-a-PD)by conjugating hydrophobic anticancer drug chlorambucil(CB)via an H_(2)O_(2)-cleavable linker 4-(hydroxymethyl)phenylboronic acid(PBA).Ce6@P(EG-a-CPBE)NPs can efficiently prevent premature drug leakage in blood circulation because of the high stability of the PBA linker under the physiological environment and facilitate the delivery of Ce6 and CB to the tumor site after intravenous injection.Upon internalization of Ce6@P(EG-a-CPBE)NPs by tumor cells,PBA is cleaved rapidly triggered by endogenous H_(2)O_(2)to release CB and Ce6.Ce6 can effectively generate abundant^(1)O_(2)under 660 nm light irradiation to synergistically kill cancer cells with CB.Concurrently,PBA can be transformed into a GSH-scavenger(quinine methide,QM)under intracellular H_(2)O_(2)and prevent the depletion of^(1)O_(2),which induces the cooperatively strong oxidative stress and enhanced cancer cell apoptosis.Collectively,such H_(2)O_(2)-responsive polymer prodrug NPs loaded with photosensitizer provide a feasible approach to enhance chemo-photodynamic synergistic cancer treatment.

GSH-responsive SN38 dimer-loaded shape-transformable nanoparticles with iRGD for enhancing chemo-photodynamic therapy

Accurate tumor targeting,deep penetration and superb retention are still the main pursuit of developing excellent nanomedicine.To achieve these requirements,a stepwise stimuli-responsive strategy was developed through co-administration tumor penetration peptide iRGD with shape-transformable and GSH-responsive SN38-dimer(d-SN38)-loaded nanoparticles(d-SN38@NPs/iRGD).Upon intravenous injection,d-SN38@NPs with high drug loading efficiency(33.92±1.33%)could effectively accumulate and penetrate into the deep region of tumor sites with the assistance of iRGD.The gathered nanoparticles simultaneously transformed into nanofibers upon 650 nm laser irradiation at tumor sites so as to promote their retention in the tumor and burst release of reactive oxygen species for photodynamic therapy.The loaded d-SN38 with disulfide bond responded to the high level of GSH in tumor cytoplasm,which consequently resulted in SN38 release and excellent chemo-photodynamic effect on tumor.In vitro,coadministering iRGD with d-SN38@NPs+laser showed higher cellular uptake,apoptosis ratio and multicellular spheroid penetration.In vivo,d-SN38@NPs/iRGD+laser displayed advanced penetration and accumulation in tumor,leading to 60.89%of tumor suppression in 4 T1 tumor-bearing mouse model with a favorable toxicity profile.Our new strategy combining iRGD with structural transformable nanoparticles greatly improves tumor targeting,penetrating and retention,and empowers anticancer efficacy.

Dual-responsive nanoparticles with transformable shape and reversible charge for amplified chemo-photodynamic therapy of breast cancer

Herein, we designed a dual-response shape transformation and charge reversal strategy with chemo-photodynamic therapy to improve the blood circulation time, tumor penetration and retention,which finally enhanced the anti-tumor effect. In the system, hydrophobic photosensitizer chlorin e6(Ce6), hydrophilic chemotherapeutic drug berberrubine(BBR) and matrix metalloproteinase-2(MMP-2) response peptide(PLGVRKLVFF) were coupled by linkers to form a linear triblock molecule BBR-PLGVRKLVFF-Ce6(BPC), which can self-assemble into nanoparticles. Then, positively charged BPC and polyethylene glycol-histidine(PEG-His) were mixed to form PEG-His@BPC with negative surface charge and long blood circulation time. Due to the acidic tumor microenvironment, the PEG shell was detached from PEG-His@BPC attributing to protonation of the histidine, which achieved charge reversal, size reduction and enhanced tumor penetration. At the same time, enzyme cutting site was exposed, and the spherical nanoparticles could transform into nanofibers following the enzymolysis by MMP-2, while BBR was released to kill tumors by inducing apoptosis. Compared with original nanoparticles, the nanofibers with photosensitizer Ce6 retained within tumor site for a longer time. Collectively,we provided a good example to fully use the intrinsic properties of different drugs and linkers to construct tumor microenvironment-responsive charge reversal and shape transformable nanoparticles with synergistic antitumor effect.

Antibiotic-based small molecular micelles combined with photodynamic therapy for bacterial infections

The appearance of multidrug-resistant bacteria and the formation of bacterial biofilms have necessitated the development of alternative antimicrobial therapeutics.Antibiotics conjugated with or embedded in nano-drug carriers show a great potential and advantage over free drugs,but the mass proportion of carriers generally exceeds 90%of the nano-drug,resulting in low drug loading and limited therapeutic output.Herein,we fabricated a nanocarrier using antibiotics as the building blocks,minimizing the use of carriermaterials,significantly increasing the drug loading content and treatment effect.Firstly,we conjugated betaine carboxylate with ciprofloxacin(CIP)through an ester bond to form the amphiphilic conjugate(CIP-CB),which self-assembled into micelles(CIP-CBMs)in aqueous solutions,with a CIP loading content as high as 65.4%and pH-induced surface charge reversal properties.Secondly,a model photosensitizer(5,10,15,20-tetraphenylporphyrin(TPP))was encapsulated in CIP-CBMs,generating infection-targeted photodynamic/antibiotic combined nanomedicines(denoted as TPP@CIP-CBMs).Upon accumulation at infection sites or in deep bacterial biofilms,the ester bond between the betaine carboxylate and CIP is cleaved to release free TPP and CIP,leading to a synergetic antibacterial and antibiofilm activity in vitro and in vivo.

Co-delivery of Cisplatin and Chlorin e6 by Poly(phosphotyrosine)for Synergistic Chemotherapy and Photodynamic Therapy

Nanoscale drug delivery systems(NDDSs)have emerged as promising carriers for combinational therapy by co-delivery of multiple drugs and modalities.However,most co-delivery systems require the use of complicated materials and formulations.Herein,we report the single use of a polymeric material,namely mPEG-block-poly(phosphotyrosine)(mPEG-b-PpY),as a multi-functional carrier for the facile fabrication of NDDS Pt/Ce6@mPEG-b-PpY(PtCeNP)for the co-delivery of cisplatin and photosensitizer chlorin e6(Ce6)via phosphato-platinum coordination andπ-πstacking,respectively.PtCeNP improves the solubility,cellular uptake,and bioavailability of both parental drugs,and showed strong synergistic antitumor efficacy both in vitro and in vivo through combined chemo-photodynamic therapy.Our results indicate that PpY is a biocompatible,multifunctional,and promising carrier material suitable for a variety of drugs and may simplify the design for co-delivery systems.

Structurally defined tandem-responsive nanoassemblies composed of dipeptide-based photosensitive derivatives and hypoxia-activated camptothecin prodrugs against primary and metastatic breast tumors

Substantial progress in the use of chemo-photodynamic nano-drug delivery systems(nanoDDS) for the treatment of the malignant breast cancer has been achieved. The inability to customize precise nanostructures, however, has limited the therapeutic efficacy of the prepared nano-DDS to date. Here,we report a structurally defined tandem-responsive chemo-photosensitive co-nanoassembly to eliminate primary breast tumor and prevent lung metastasis. This both-in-one co-nanoassembly is prepared by assembling a biocompatible photosensitive derivative(pheophorbide-diphenylalanine peptide, PPADA) with a hypoxia-activated camptothecin(CPT) prodrug [(4-nitrophenyl) formate camptothecin, NCPT]. According to computational simulations, the co-assembly nanostructure is not the classical core-shell type, but consists of many small microphase regions. Upon exposure to a 660 nm laser,PPA-DA induce high levels of ROS production to effectively achieve the apoptosis of normoxic cancer cells. Subsequently, the hypoxia-activated N-CPT and CPT spatially penetrate deep into the hypoxic region of the tumor and suppress hypoxia-induced tumor metastasis. Benefiting from the rational design of the chemo-photodynamic both-in-one nano-DDS, these nanomedicines exhibit a promising potential in the inhibition of difficult-to-treat breast tumor metastasis in patients with breast cancer.