Tumor‑Anchoring Drug‑Loaded Fibrous Microspheres for MR Imaging‑Guided Local Chemotherapy and Metastasis Inhibition

Unobtrusive metastasis and invasion of malignant tumors are major causes for the death of cancer patients,and unfortunately the lack of specificity and abrupt release of anticancer drugs applied to the primary tumors are causing serious side effects in cancer management.Hence,the development of controlled local drug delivery systems that can effectively treat primary tumors and inhibit tumor metastasis is of critical importance for improved cancer therapeutics.Herein,we developed hyaluronic acid(HA)-modified porous fibrous microspheres as a drug delivery system with the functions of long-acting local chemotherapy,tumor metastasis inhibition and magnetic resonance(MR)imaging.Poly(lactic-co-glycolic acid)(PLGA)short fibers obtained by combined electrospinning and homogenization techniques were successfully modified with gadolinium(Gd^(3+))chelates and HA,which were subsequently mixed with doxorubicin(DOX)to obtain the multifunctional drug-loaded fibrous microspheres of DOX-PLGA-PEI-DTPA-Gd/HA(DOX−PGH)by electrospray and further crosslinking.The developed DOX−PGH microspheres with an average diameter of 118.8μm possess good structural stability and a high r1 relaxivity,and can achieve long-term DOX release.The cellular and animal experiments demonstrated that the DOX−PGH microspheres could facilitate targeted delivery of DOX to accelerate 4T1 cell death while reducing cancer cell metastasis due to the cooperative actions of long-term DOX-mediated chemotherapy and the fibrous microsphere-induced tumor anchoring to likely avoid primary tumor cell shedding,and render MR imaging of tumors during the treatment.The developed DOX−PGH microspheres may represent one of the updated local tumor chemotherapy formulations for improved tumor therapy with justified antitumor and anti-metastasis efficacy.

Feasibility and efficacy evaluation of metallic biliary stents eluting gemcitabine and cisplatin for extrahepatic cholangiocarcinoma

BACKGROUND Effective endoscopic management is fundamental for the treatment of extrahepatic cholangiocarcinoma(ECC).However,current biliary stents that are widely used in clinical practice showed no antitumor effect.Drug-eluting stents(DESs)may achieve a combination of local chemotherapy and biliary drainage to prolong stent patency and improve prognosis.AIM To develop novel DESs coated with gemcitabine(GEM)and cisplatin(CIS)-coloaded nanofilms that can maintain the continuous and long-term release of antitumor agents in the bile duct to inhibit tumor growth and reduce systemic toxicity.METHODS Stents coated with different drug-eluting components were prepared by the mixed electrospinning method,with poly-L-lactide-caprolactone(PLCL)as the drug-loaded nanofiber membrane and GEM and/or CIS as the antitumor agents.Four different DESs were manufactured with four drug-loading ratios(5%,10%,15%,and 20%),including bare-loaded(PLCL-0),single-drug-loaded(PLCL-GEM and PLCL-CIS),and dual-drug-loaded(PLCL-GC)stents.The drug release property,antitumor activity,and biocompatibility were evaluated in vitro and in vivo to confirm the feasibility and efficacy of this novel DES for ECC.RESULTS The in vitro drug release study showed the stable,continuous release of both GEM and CIS,which was sustained for over 30 d without an obvious initial burst,and a higher drug-loaded content induced a lower release rate.The drug-loading ratio of 10%was used for further experiments due to its ideal inhibitory efficiency and relatively low toxicity.All drug-loaded nanofilms effectively inhibited the growth of EGI-1 cells in vitro and the tumor xenografts of nude mice in vivo;in addition,the dual-loaded nanofilm(PLCL-GC)had a significantly better effect than the single-drug-loaded nanofilms(P<0.05).No significant differences in the serological analysis(P>0.05)or histopathological changes were observed between the single-loaded and drug-loaded nanofilms after stent placement in the normal porcine biliary tract.CONCLUSION This novel PLCL-GEM and CIS-eluting stent maintains continuous,stable drug release locally and inhibits tumor growth effectively in vitro and in vivo.It can also be used safely in normal porcine bile ducts.We anticipate that it might be considered an alternative strategy for the palliative therapy of ECC patients.

Polysaccharide based supramolecular injectable hydrogels for in situ treatment of bladder cancer

Implantable system maximizes drug concentration and continuously releases drugs near the tumor,which is an effective tool to solve the difficult retention of chemotherapy drugs in bladder cancer.In this work,a novel polysaccharide supramolecular injectable hydrogel(CCA hydrogels for short)is rapidly constructed by simply mixing cationic chitosan,anionic sulfobutyl etherβ-cyclodextrin(SBE-β-CD)and a trace amount of silver ions.The injected hydrogel reconstituted and regained its shape in less than 1 h,and it can still maintain the elasticity suitable for the human body.By packaging the drug directly,the gel achieves a high concentration of doxorubicin,an anticancer drug.Using MB49-luc cells as the model of bladder tumor for anti-tumor in vivo,the CCA-DOX gel has obvious inhibitory effect on bladder tumor,and its inhibitory effect is much greater than that of free DOX.Therefore,this self-healing injectable hydrogel has great potential for in situ treatment of bladder cancer.

Practical strategy to construct anti-osteosarcoma bone substitutes by loading cisplatin into 3D-printed titanium alloy implants using a thermosensitive hydrogel

Surgical resection and perioperative adjuvant chemotherapy-based therapies have improved the prognosis of patients with osteosarcoma;however,intraoperative bone defects,local tumour recurrence,and chemotherapy-induced adverse effects still affect the quality of life of patients.Emerging 3D-printed titanium alloy(Ti6Al4V)implants have advantages over traditional implants in bone repair,including lower elastic modulus,lower stiffness,better bone conduction,more bone in-growth,stronger mechanical interlocking,and lager drug-loading capacity by their inherent porous structure.Here,cisplatin,a clinical first-line anti-osteosarcoma drug,was loaded into Ti6Al4V implants,within a PLGA-PEG-PLGA thermo-sensitive hydrogel,to construct bone substitutes with both anti-osteosarcoma and bone-repair functions.The optimal concentrations of cisplatin(0.8 and 1.6 mg/mL)were first determined in vitro.Thereafter,the anti-tumour effect and biosafety of the cisplatin/hydrogel-loaded implants,as well as their bone-repair potential were evaluated in vivo in tumour-bearing mouse,and bone defect rabbit models,respectively.The loading of cisplatin reduced tumour volume by more than two-thirds(from 641.1 to 201.4 mm3)with negligible organ damage,achieving better anti-tumour effects while avoiding the adverse effects of systemic cisplatin delivery.Although bone repair was hindered by cisplatin loading at 4 weeks,no difference was observed at 8 weeks in the context of implants with versus without cisplatin,indicating acceptable long-term stability of all implants(with 8.48%-10.04%bone in-growth and 16.94%-20.53%osseointegration).Overall,cisplatin/hydrogel-loaded 3D-printed Ti6Al4V implants are safe and effective for treating osteosarcoma-caused bone defects,and should be considered for clinical use.