NIR-triggered thermo-responsive biodegradable hydrogel with combination of photothermal and thermodynamic therapy for hypoxic tumor

Hypoxia is a typical feature of solid tumors,which highly limits the application of the oxygen-dependent therapy.Also,the dense and hyperbaric tumor tissues impede the penetration of nanoparticles into the deep tumor.Thereby,we designed a novel localized injectable hydrogel combining the photothermal therapy(PTT)and the thermodynamic therapy(TDT),which is based on the generation of free radicals even in the absence of oxygen for hypoxic tumor therapy.In our study,gold nanorods(Au NRs)and 2,2-Azobis[2-(2-imidazalin-2-yl)propane]dihydrochlaride(AIPH)were incorporated into the hydrogel networks,which were formed by the copolymerization of hydrophobic N-isopropyl acrylamide(NIPAM)and hydrophilic glycidyl methacrylate modified hyaluronic acid(HAGMA)to fabricate an injectable and near-infrared(NIR)responsive hydrogel.The crosslinked in situ forming hydrogel could not only realize PTT upon the NIR laser irradiation,but also generate free radicals even in hypoxic condition.Meanwhile the shrink of hydrogels upon thermal could accelerate the generation of free radicals to further damage the tumors,achieving the controlled drug release on demand.The designed hydrogel with a sufficient loading capacity,excellent biocompatibility and negligible systemic toxicity could serve as a long-acting implant for NIR-triggered thermo-responsive free radical generation.The in vitro cytotoxicity result and the in vivo antitumor activity illustrated the excellent therapeutic effect of hydrogels even in the absence of oxygen.Therefore,this innovative oxygen-independent platform combining the antitumor effects of PTT and TDT would bring a new insight into hypoxic tumor therapy by the application of alkyl free radical.

Investigation of physicochemical properties and in-vitro in-vivo evaluation of agomelatine polymorphs

In the present study,Form I,Form II and Form III of agomelatine were prepared to investigate the variability of polymorphs,then the in-vitro in-vivo correlation were established.The presence of three polymorphs of agomelatine was corroborated through studies by XRPD,TGA and DSC.All the forms obtained were then subjected to the powder and intrinsic dissolution tests.The IDR ranked in the order of Form III>Form I>Form II.Form I and Form III both underwent solvent-mediated phase transformation(SMPT)to Form II during dissolution and the transition points were 62 and 45 min,respectively.Pharmacokinetic profiles were acquired after oral administration of tablets,showing that the ka and AUC0e12 h of Form I,Form II,Form III were 0.58
0.11,0.34
0.05,0.74
0.07 h1 and 296.25
49.39,186.05
45.93,331.16
54.74 ng*h/ml,respectively.Good linearities between IDR and ka,IDR and AUC were established,suggesting that the agomelatine polymorphic forms with faster dissolution rates in-vitro would increase the rate and extent of oral absorption in-vivo.These results demonstrated that IDR was predictive in estimating the relative bioavailability of agomelatine polymorphic forms.

The preparation and the in-vitro pharmacodynamics study of the intracapsular sustained-release preparations for the prevention of posterior capsule opacification

Docetaxel-loaded sustained-release preparation based on 2-Hydroxyethyl methacrylate(HEMA)and Methyl methacrylate(MMA)cross-linked copolymer(P(HEMA-co-MMA))was prepared to examine the potential use for preventing posterior capsule opacification(PCO).The preparations were prepared by polymerizing the mixture of HEMA,MMA,cross-linking agent(EGDMA),initiator(AIBN)and docetaxel.The influence factors and mechanism of drug release were studied in the experiments.FT-IR,X-RD and SEM methods were used to characterize the polymer(P(HEMA-co-MMA))and docetaxel-loaded sustained-release preparations.Biocompatibility of P(HEMA-co-MMA)and in-vitro effect of docetaxel-loaded sustained-release preparations were also evaluated.The results showed that docetaxel could release sustainedly from these preparations prepared by cross-linking polymerization.And the release rate could be accelerated by increasing the MMA ratio or EGDMA ratio of the polymer.Release mechanism of docetaxel fitted the Higuchi model well.The results of IR and X-RD showed that only a hydrogen bond was formed between docetaxel and P(HEMA-co-MMA).Docetaxel dispersed in P(HEMA-co-MMA)in amorphous form.The elution test showed that P(HEMA-co-MMA)had good biocompatibility and the in-vitro pharmacodynamics study proved that docetaxel could release stably from the preparations and inhibit HLECs’proliferation.The docetaxel-loaded sustained-release preparations proved to be a promising therapy for preventing PCO.These results also lay a theoretical and experimental foundation for the future.

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.

“NIR-triggered ROS storage”photodynamic intraocular implant for high-efficient and safe posterior capsular opacification prevention

Posterior capsular opacification(PCO)is the leading cause of vision loss after cataract,mainly caused by the adhesion,proliferation and trans-differentiation of post-operative residual lens epithelial cells(LECs).Effective PCO prevention remains a huge challenge to ophthalmologists and researches for decades.Herein,we developed a“NIR-triggered ROS storage”intraocular implant(CTR-Py-Pp IX)based on capsular tension ring(CTR),which is concurrently linked with photosensitizer protophorphyrin IX(Pp IX)and energy storage2-pyridone derivative(Py),to guarantee instantaneous and sustainable ROS generation for LECs killing,aiming to achieve more efficient and safer photodynamic therapy(PDT)to effectively prevent PCO.The silylated Pp IX-Si and Py-Si were covalently conjugated to the plasma activated CTR surface to obtain CTR-Py-Pp IX.Results demonstrated that CTR-Py-Pp IX had dual functions of PDT and battery,in which Pp IX could generate ROS extracellularly under irradiation,with one part directly inhibiting LECs by lipid peroxidation(LPO)induction of cell membranes.Meanwhile,the excess ROS stored in Py could be continuously released to amplify LPO levels after the irradiation was removed.Ultimately,the proliferation of LECs in capsular bag was completely inhibited under mild irradiation conditions,achieving a sustainable and controlled PDT effect for effective PCO prevention with good biocompatibility.This NIR-triggered ROS storage intraocular implant would provide a more efficient and safer approach for long-term PCO prevention.

Bone-seeking nanoplatform co-delivering cisplatin and zoledronate for synergistic therapy of breast cancer bone metastasis and bone resorption

The"vicious cycle"established between tumor growth and osteolysis aggravates the process of breast cancer bone metastasis,leading to life-threatening skeletal-related events that severely reduce survival and quality of life.To effectively interrupt the"vicious cycle",innovative therapeutic strategies that not only reduce osteolysis but also relieve tumor burden are urgently needed.Herein,a bone-seeking moiety,alendronate(ALN),functionalized coordination polymer nanoparticles(DZ@ALN)co-delivering cisplatin prodrug(DSP)and antiresorptive agent zoledronate(ZOL)via Zn2+crosslinking for combination therapy was reported.The versatile DZ@ALN with a diameter of about 40 nm can cross the fissure in the bone marrow sinus capillaries,and possesses an excellent bone-seeking ability both in vitro and in vivo.Additionally,DZ@ALN could synergistically inhibit the proliferation of cancer cells,suppress the formation of osteoclast-like cells and induce the apoptosis of osteoclasts in vitro.Importantly,it could preferentially accumulate in bone affected site,remarkably inhibit the proliferation of tumor cells,relieving bone pain,and significantly inhibit the activation of osteoclasts,protecting the bone from destruction in vivo,eventually leading to the breakdown of"vicious cycle"without inducing obvious systemic toxicity.This innovative nanoagent combines chemotherapy and osteolysis inhibition,exhibiting an inspiring strategy for effective treatment of bone metastasis.