Tingsheng Lin

In Situ Floating Hydrogel for Intravesical Delivery of Adriamycin Without Blocking Urinary Tract

Drug solution is commonly used in conventional intravesical instillation. However, most of them would be easily eliminated by voiding, which significantly limit their efficacy. Recent advances in intravesical drug delivery are to use hydrogels as drug reservoir to extend the drug residence time in bladder. However, because of the high viscosity of hydrogel, urinary obstruction is usually existed during the intravesical instillation. To overcome these, we developed a floating hydrogel for the delivery of Adriamycin (ADR). The floating hydrogel was made of ADR, thermosensitive polymer (Poloxamer 407) and NaHCO₃, which was liquid at low temperature, whereas formed gel at high temperature. In the presence of H⁺, NaHCO₃ decomposed and produced CO₂ that attached on the surface of hydrogel and helped the hydrogel float on the urine. Hence, the urinary tract will not be blocked. Meanwhile, the encapsulated ADR released in a controlled manner. These results suggest that the floating gel may have promising applications in intravesical therapy for bladder cancer.

A Floating Hydrogel System Capable of Generating CO2 Bubbles to Diminish Urinary Obstruction After Intravesical Instillation

ABSTRACTAimIntravesical instillation is commonly used to decrease the tumor recurrence after transurethral resection. However, most drug solutions would be eliminated from bladder after the first voiding of urine, so its clinical efficacy is limited. To overcome this obstacle, we developed a floating hydrogel system for controlled delivery of antitumor drugs.MethodsThe floating hydrogel was made of Adriamycin, thermo-sensitive polymer (Poloxamer 407) and NH4HCO3, which was liquid at low temperature while forming hydrogel at high temperature. Meanwhile, at high temperature, NH4HCO3 decomposed to produce CO2 bubbles, which helped hydrogel float in bladder without urinary obstruction.ResultsThe mixture containing 45% P407 and 6% NH4HCO3 was selected as the optimal formulation. At 37°C, the mixture formed hydrogel and produced many bubbles which could be observed by B ultrasound. The vitro study showed that the antitumor drug Doxorubicin was released in a controlled manner. After the mixture was instilled into rabbit bladder, it formed hydrogel and floated in the bladder. The bladder stimuli was reduced and antitumor drugs could be released continuously in the bladder.ConclusionOur results suggested that the floating hydrogel was a feasible intravesical drug delivery system and may have application prospects in intravesical therapy for bladder cancer.

O2-generating MnO2 nanoparticles for enhanced photodynamic therapy of bladder cancer by ameliorating hypoxia

Photodynamic therapy (PDT) is an emerging effective treatment for cancer. However, the great promise of PDT for bladder cancer therapy has not yet been realized because of tumor hypoxia. To address this challenge, we fabricated O2-generating HSA-MnO2-Ce6 NPs (HSA for human serum albumin, Ce6 for chlorin e6, and NPs for nanoparticles) to overcome tumor hypoxia and thus enhance the photodynamic effect for bladder cancer therapy. Methods: The HSA-MnO2-Ce6 NPs were prepared. We investigated the O2 generation of NPs in vitro and in vivo. The orthotopic bladder cancer model in C57BL/6 mice was established for in vivo study, and dual-modal imaging of NPs were demonstrated. Therapeutic efficacy of NPs for bladder cancer was evaluated. Results: HSA-MnO2-Ce6 NPs had an excellent performance in generating O2 in vitro upon reaction with H2O2 at endogenous levels. Moreover, 1O2 generation was increased two-fold by using HSA-MnO2-Ce6 NPs instead of HSA-Ce6 NPs in the presence of H2O2 under 660 nm laser irradiation. In vitro cell viability assays showed that HSA-MnO2-Ce6 NPs themselves were non-toxic but greatly enhanced PDT effects on bladder cancer cells under laser irradiation. In vivo near-infrared (NIR) fluorescence and magnetic resonance (MR) imaging suggested the excellent bladder tumor-targeting property of HSA-MnO2-Ce6 NPs. O2 content in orthotopic bladder cancer was increased 3.5-fold after injection of HSA-MnO2-Ce6 NPs as compared with pre-injection. Given the excellent tumor-targeting ability and negligible toxicity, HSA-MnO2-Ce6 NPs were then used to treat orthotopic bladder cancer by PDT. The PDT with HSA-MnO2-Ce6 NPs showed remarkably improved therapeutic efficacy and significantly prolonged lifetime of mice as compared with controls. Conclusion: This study not only demonstrated the great potential of HSA-MnO2-Ce6 NPs for bladder cancer photodynamic ablation but also provided a new therapeutic strategy to overcoming tumor hypoxia.

Highly effective photothermal chemotherapy with pH-responsive polymer-coated drug-loaded melanin-like nanoparticles

Dopamine is a neurotransmitter commonly used in clinical treatment. Polydopamine (PDA) has excellent histocompatibility and biosafety and can efficiently convert near-infrared reflection (NIR) to thermal energy. In this study, PDA was used as a promising carrier, and pH-responsive polymer-coated drug-loaded PDA nanoparticles (NPs; doxorubicin@ poly(allylamine)-citraconic anhydride [Dox@PAH-cit]/PDA NPs) were developed. As expected, the Dox@PAH-cit/PDA NPs exhibited excellent photothermal efficiency. In addition, at a low pH condition, the loaded Dox was released from the NPs due to the amide hydrolysis of PAH-cit. Upon NIR exposure (808 nm), the temperature of the NP solution rapidly increases to kill tumor cells. Compared with unbound chemotherapy drugs, the NPs have a stronger cell uptake ability. In vivo, the PDA NPs were able to efficiently accumulate at the tumor location. After intravenous administration and NIR exposure, tumor growth was significantly inhibited. In summary, the present investigation demonstrated that the Dox@PAH-cit/PDA NPs presented highly effective photothermal chemotherapy for prostate cancer.

Comparison of the complications of traditional 12 cores transrectal prostate biopsy with image fusion guided transperineal prostate biopsy

BackgroundTo compare the complications of traditional transrectal (TR) prostate biopsy and image fusion guided transperineal (TP) prostate biopsy in our center.MethodsTwo hundred and fourty-two patients who underwent prostate biopsy from August 2014 to January 2015were reviewed. Among them, 144 patients underwent systematic 12-core transrectal ultrasonography (TRUS) guided prostate biopsy (TR approach) while 98 patients underwent free-hand transperineal targeted biopsy with TRUS and multi-parameter magnetic resonance imaging (mpMRI) fusion images (TP approach). The complications of the two groups were presented and a simple statistical analysis was performed to compare the two groups.ResultsThe cohort of our study include242 patients, including 144 patients underwent TR biopsies while 98 patients underwentTP biopsies. There was no significant difference of major complications, including sepsis, bleeding and other complication requiring admissionbetween the two groups (P > 0.05). The incidence rate of infection and rectal bleeding in TR was much higher than TP (p < 0.05), but the incidence rate of perineal swelling in TP was much higher than TR (p < 0.05). There were no significant differences of minor complications including hematuria, lower urinary tract symptoms (LUTS), dysuria, and acuteurinary retention between the two groups (p > 0.05).ConclusionThe present study supports the safety of both techniques. Free-handTP targeted prostate biopsy with real-time fusion imaging of mpMRI and TR ultrasound is a good approach for prostate biopsy.

miR34a/GOLPH3 Axis abrogates Urothelial Bladder Cancer Chemoresistance via Reduced Cancer Stemness

Rationale: Chemoresistance and subsequent recurrence of human urothelial bladder cancer (UBC) is partially driven by a subpopulation of tumor initiating cells, namely cancer stem cells (CSCs). However, the underlying molecular mechanism in chemotherapy-induced CSCs enrichment and following chemoresistance and recurrence remains largely unclear. Methods: Gemcitabine and cisplatin (GC) chemoresistant cell lines (T24 GC 3rd and 5637 GC 3rd cells) and the chemo-sensitive UBC cell lines T24 and 5637 were established in vivo for the investigation of acquired resistance mechanisms. The role of miR34a/GOLPH3 axis in regulating UBC chemoresistance and recurrence was evaluated in cell and animal models. The expression levels of miR34a/GOLPH3 axis and CSCs markers were assayed in specimens of UBC. The association of GOLPH3 with clinicopathologic features and prognosis was analysed. Results: RT-PCR and western blotting confirmed that the expression levels of miR34a were decreased and GOLPH3 were increased in GC chemoresistant UBC cell lines. Downregulation of miR34a resulted in the overexpression of GOLPH3, which is a target gene of miR34a confirmed by luciferase experiment. The ectopic expression of miR34a decreased the stem cell properties of chemoresistant UBC cells and re-sensitized these cells to GC treatment in vitro and in vivo. Moreover, miR34a/GOLPH3 axis has obvious clinical relevance with prognosis and recurrence in human UBC patients with standard GC chemotherapy. Conclusion: Our results suggest that miR34a/GOLPH3 axis exert key role in CSCs involved UBC drug resistance and recurrence and warrant further development as a promising therapeutic approach in treating drug-resistant UBC.

Drug delivery system based on dendritic nanoparticles for enhancement of intravesical instillation

Intravesical instillation of antitumor agents following transurethral resection of bladder tumors is the standard strategy for the treatment of superficial bladder cancers. However, the efficacy of current intravesical instillation is limited partly due to the poor permeability of the urothelium. We therefore aimed to develop a high-penetrating, target-releasing drug delivery system to improve the efficacy of intravesical instillation. PAMAM, a dendrimer, were conjugated with polyethylene glycol (PEG) to form PEG-PAMAM complex as a nanocarrier. Doxorubicin (DOX) was then encapsulated into PEG-PAMAM to generate DOX-loaded PEG-PAMAM nanoparticles (PEG-PAMAM-DOX). Our results indicated that the PEG-PAMAM was a stable nanocarrier with small size and great biosafety. The release of DOX from PEG-PAMAM-DOX was sluggish but could be effectively triggered in an acid microenvironment (pH =5.0). As a drug carrier, PEG-PAMAM could penetrate mice bladder urothelium effectively and increase the amount of DOX within the bladder wall after intravesical instillation. The antitumor effect of PEG-PAMAM-DOX was evaluated using an orthotopic bladder cancer model in mice. Compared to free DOX, PEG-PAMAM-DOX showed significantly improved efficacy of DOX for intravesical instillation with limited side effects. In conclusion, we successfully developed a PEG-PAMAM-based drug delivery system to enhance the antitumor effect of intravesical instillation.

Floating Hydrogel with Self-Generating Micro-Bubbles for Intravesical Instillation

Intravesical instillation is the main therapy for bladder cancer and interstitial cystitis. However, most drug solutions are eliminated from bladder after the first voiding of urine. To solve this problem, we proposed a floating hydrogel with self-generating micro-bubbles as a new delivery system. It floated in urine, avoiding the urinary obstruction and bladder irritation that ordinary hydrogels caused. In this study, we abandoned traditional gas-producing method like chemical decomposition of NaHCO3, and used the foamability of Poloxamer 407 (P407) instead. Through simple shaking (just like shaking SonoVue for contrast-enhanced ultrasound in clinical), the P407 solution will “lock” many micro-bubbles and float in urine as quickly and steadily as other gas producing materials. In vivo release experiments showed that drug was released continually from hydrogel for 10 h during the erosion process. Thus, the residence time of drug in bladder was prolonged and drug efficacy was improved. In vivo efficacy study using rabbit acute bladder injury model showed that prolonged drug residence time in bladder increased the efficiency of heparin in the protection of bladder mucosal permeability. Therefore, our floating hydrogel system with self-generating micro-bubbles was single-component, simply prepared and efficacy enhancing, successfully exempting users from worries on safety and clinical efficiency from bench to bedside.