Local administration of shikonin improved the overall survival in orthotopic murine glioblastoma models with temozolomide resistance

BACKGROUND

Glioblastoma is a type of intracranial malignancy. Shikonin, a Chinese traditional medicine, has been shown to have anti-tumor efficacy toward human glioblastoma cells in vitro. However, shikonin cannot easily cross the blood-brain barrier. To address this issue, we evaluated the anti-tumor effects of direct intracranial infusion of shikonin in in vivo orthotopic syngeneic murine glioblastoma models using C57BL/6 mice.

MATERIALS AND METHODS

The cytotoxic effects of shikonin against murine glioblastoma cells, SB28 and CT-2A, were reported resistance to temozolomide, were evaluated using an allophycocyanin-conjugated annexin V and propidium iodide assay with flow cytometry. Impedance-based real-time cell analysis (RTCA) was used to analyze the inhibitory effects of shikonin on growth and proliferation. To evaluate the anti-tumor activity of shikonin in vivo, we used orthotopic syngeneic murine glioblastoma models with SB28 and CT-2A cells.

RESULTS

In flow cytometry-based cytotoxic assays, shikonin induced apoptosis. RTCA indicated that shikonin decreased the cell index of murine glioblastoma cells, SB28 and CT-2A, in a dose-dependent manner (p < 0.0001 for both cell lines), while temozolomide did not (p = 0.91 and 0.82, respectively). In murine glioblastoma models, SB28 and CT-2A, direct intracranial infusion of shikonin, as a local chemotherapy, improved the overall survival of mice in a dose-dependent manner compared with control groups (p < 0.0001 and p = 0.02, respectively). While temozolomide did not (p = 0.48 and 0.52, respectively).

CONCLUSIONS

The direct intracranial infusion of shikonin has potential as a local therapy for patients with glioblastoma.

5-Fluorouracil crystal-incorporated, pH-responsive, and release-modulating PLGA/Eudragit FS hybrid microparticles for local colorectal cancer-targeted chemotherapy

5-Fluorouracil (5-FU) is a widely used chemotherapeutic agent for colorectal cancer (CRC) owing to its potent anticancer effects. However, severe systemic side effects and poor drug accumulation in the CRC tissues limit its efficacy. This study aimed to develop 5-FU crystal-incorporated, pH-responsive, and release-modulating poly(d,l-lactide-co-glycolide)/Eudragit FS hybrid microparticles (5FU-EPMPs) for the local CRC-targeted chemotherapy. Approximately 150 μm 5FU-EPMPs were fabricated via the S/O/W emulsion solvent evaporation method, with 7.93 ± 0.24% and 87.23 ± 2.64% 5-FU loading and encapsulation efficiencies, respectively. Drug release profiles in a simulated pH environment of the gastrointestinal tract revealed that premature 5-FU release in the stomach and small intestine was prevented, thereby minimizing systemic 5-FU absorption. After reaching the colon, 5-FU was continuously released for >15 h, allowing long-term exposure of CRC tissues to sufficient 5-FU concentrations. Furthermore, in a CRC mouse model, the 5FU-EPMPs showed potent inhibition of tumor growth without signs of systemic toxicity. Thus, the 5FU-EPMPs represent a promising drug delivery system for local CRC-targeted chemotherapy.

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.

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Vehiculated within PLGA-PEG-PLGA hydrogel, cisplatin can be conveniently loaded into 3D-printed Ti₆Al₄V implants.

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The cisplatin/hydrogel-loaded implants are safe and show a good anti-tumour potential both in vitro and in vivo.

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This strategy has better anti-osteosarcoma effects and fewer side effects than the conventional cisplatin delivery method.

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Cisplatin loading does not decrease the bone repair effect of 3D-printed Ti₆Al₄V implants 8 weeks after surgery.

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As the components of the implants are non-toxic, this strategy has great potential for clinical translation.

Complete rejection of large established breast cancer by local immunochemotherapy with T cell activation against neoantigens

Cancer immunotherapies, including immune checkpoint blockage and adoptive transfer of CAR-T cells, have achieved historical successes for many kinds of malignancy. However, a minority of patients survive long term over 5 years without relapse, perhaps owing to tumor heterogeneity and potent immunosuppression in the tumor microenvironment. Here, using an established mouse tumor model of triple-negative 4T1 breast cancer, we show that local immunochemotherapy triggers powerful local and systemic antitumor immunity. Paraneoplastic injection of CpG, α-OX40, and anthracycline completely eliminated both local and distant large established 4T1 breast cancer without obvious relapse. Analysis of the immune cells at tumor tissues, draining lymph nodes, and spleens revealed that the local treatment increased the infiltration of CD4⁺ and CD8⁺ T cells in all three tissues and inhibited the accumulation of myeloid-derived suppressor cells in the spleen in a delayed response. Most importantly, this treatment triggered systemic T cell response against 4T1 tumors and some of their neoantigen epitopes as detected by IFN-γ ELISpot and intracellular cytokine assays in splenocytes. Furthermore, T cells showed specific cytotoxic activity against 4T1 tumor cells in vitro. In general, this local immunochemotherapy provides a new approach to target highly diverse neoantigens in various types of cancers without complicated and expensive antigen identification via next-generation sequencing.

Bone cement as a local chemotherapeutic drug delivery carrier in orthopedic oncology: A review

Metastatic bone lesions are common among patients with advanced cancers. While chemotherapy and radiotherapy may be prescribed immediately after diagnosis, the majority of severe metastatic bone lesions are treated by reconstructive surgery, which, in some cases, is followed by postoperative radiotherapy or chemotherapy. However, despite recent advancements in orthopedic surgery, patients undergoing reconstruction still have the risk of developing severe complications such as tumor recurrence and reconstruction failure. This has led to the introduction and evaluation of poly (methyl methacrylate) and inorganic bone cements as local carriers for chemotherapeutic drugs (usually, antineoplastic drugs (ANPDs)). The present work is a critical review of the literature on the potential use of these cements in orthopedic oncology. While several studies have demonstrated the benefits of providing high local drug concentrations while minimizing systemic side effects, only six studies have been conducted to assess the local toxic effect of these drug-loaded cements and they all reported negative effects on healthy bone structure. These findings do not close the door on chemotherapeutic bone cements; rather, they should assist in materials selection when designing future materials for the treatment of metastatic bone disease.

Ocular surface complications of local anticancer drugs for treatment of ocular tumors

Local chemotherapy is increasingly used, either in combination with surgery or as monotherapy, for management of ocular tumors. Yet many of the local chemotherapeutic agents used for ocular tumors are cytotoxic drugs that are frequently associated with toxicities in normal ocular tissues. Understanding and managing these side effects are important because they affect treatment tolerability, outcome and quality of vision. Herein, we review local anticancer drugs administered for the treatment of ocular tumors, with an emphasis on their toxicities to the ocular surface, adnexa and lacrimal drainage system. We provide the underlying mechanisms and management strategies for the ocular side effects. Recent innovations in anticancer immunotherapy and ocular drug delivery systems also are discussed as new potential therapeutic modalities for alleviation of side effects.

Survival Benefit of Radiofrequency Ablation with Intratumoral Cisplatin Administration in a Rabbit VX2 Lung Tumor Model

PURPOSE

This study evaluated the survival benefit of a combination therapy with radiofrequency ablation (RFA) and intratumoral cisplatin (ITC) administration for lung tumors by using a rabbit VX2 tumor model.

MATERIALS AND METHODS

Experiments were approved by the institutional animal care committee. VX2 tumor suspension was injected into the lungs of Japanese white rabbits under CT guidance to create a lung tumor model. Thirty-two rabbits bearing a transplanted VX2 lung tumor were randomly assigned to four groups of eight: control (untreated); RFA alone; ITC alone; and RFA with ITC. All treatments were performed one week after tumor transplantation. Kaplan-Meier survival curves were compared by the log-rank test.

RESULTS

The median survival time was 24.5 days (range 17-33 days) in the control group, 40 days (30-80 days) in the RFA alone group, 31.0 days (24-80 days) in the ITC alone group, and not reached (53-80 days) in the RFA with ITC group. The median survival was significantly longer with the RFA/ITC combination compared to the control group (P < 0.001), RFA alone (P = 0.034), and ITC alone (P = 0.004). The survival time after RFA alone was also significantly longer than that of the control group (P < 0.001). There was no significant difference in tumor size or the rate of pneumothorax between each group.

CONCLUSION

RFA prolonged the survival of rabbits with lung VX2 tumors when combined with ITC.

Management of lymph node metastasis via local chemotherapy can prevent distant metastasis and improve survival in mice

Management of lymph node metastasis (LNM) by conventional modalities such as radiotherapy and systemic chemotherapy exhibit limited LNM selectivity and therefore can cause off-target adverse events. While development of LNM-specific drug delivery systems has tremendous potential to provide a safer treatment modality and improve cancer treatment, precise assessment of therapeutic efficacy and implications has been challenging due to lack of a suitable preclinical model. Here, we established an experimental LNM model in mice by directly seeding cancer cells into a lymph node (LN), which developed spontaneous LNM-borne distant metastasis (DM) in the absence of a primary tumor. In the model, early, but not late, management of LNM before thereof tumor cells systemically disseminated could confer significant survival benefit, which suggests that time to LNM management is critical. Systematic comparative assessment of various local drug delivery systems revealed that a micellar formulation could achieve highly LNM-specific delivery of a chemotherapeutic agent, which was superior to systemic chemotherapy, effective at a very low dose, and safe. This study suggests not only that the experimental LNM model provides a useful preclinical model to study LNM management and its therapeutic implications but also that micelles are a promising drug delivery system for LNM management via local administration.

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.

Electrospun nanofibers for local anticancer therapy: Review of in vivo activity

Currently, chemotherapy is the most common treatment for oncological diseases. Systemic administration of chemotherapeutics provides an easy and effective distribution of the active agents throughout the patient's body, however organs may be severely impaired by serious life-threatening side effects. In many oncological diseases, particularly solid tumors, the local application of chemotherapeutics would be advantageous. Recently, nanofibrous materials as local drug delivery systems have attracted much attention. They have considerable potential in the treatment of various cancers as they can provide a high concentration of the drug at the target site for a prolonged time, thereby lowering total exposure and adverse effects. The present review describes the specifics of drug delivery to the tumor microenvironment, basic characteristics of nanofibrous materials and their preparation, and comprehensively summarizes recent scientific reports concerning in vivo experiments with drug-loaded electrospun nanofibrous systems designed for local anticancer therapy.

Minimally invasive surgery through the interlaminar approach in the treatment of spinal tuberculosis: A retrospective study of 31 patients

The aim of this study was to evaluate the efficacy of minimally invasive spinal decompression combined with local chemotherapy in treating patients with thoracic/lumbar tuberculosis (TB) and abscess compression of the spinal canal. Clinical data of 31 patients with thoracic/lumbar TB and spinal epidural abscess, admitted to our hospital between December 2005 and June 2014 were retrospectively analyzed. All patients received initial conservative treatment but achieved unsatisfactory results and then underwent minimally invasive spinal canal decompression, focus debridement and catheter drainage through a posterior interlaminar approach. Postoperatively, a short-course (1-2months) of local chemotherapy was given. The patients were followed up on a regular basis. The neurologic status was graded according to the American Spinal Injury Association (ASIA) score system. Kyphotic deformity was evaluated using Cobb angle measurement. Patients were followed up for an average of 37months (range: 12-96months). At the last follow-up, ASIA scores were improved in all patients, and there was a mild increase in the Cobb angle, but satisfactory spinal stabilization was achieved. Hepatorenal function, erythrocyte sedimentation rate and C-reactive protein levels all returned to normal. One complication was observed, where the patient had worsened deficit postoperatively but achieved a satisfactory recovery (from Grade C to Grade E) one year after a second surgery. Minimally invasive spinal canal decompression combined with local chemotherapy appears to be an effective treatment for patients with thoracic/lumbar TB and abscess compression in the spinal canal.

The use of cisplatin-loaded mucoadhesive nanofibers for local chemotherapy of cervical cancers in mice

Polymer-based local drug delivery system may be suitable for the treatment of cervix cancer. A pilot study was carried out to examine the efficacy of cisplatin-loaded poly(ethylene oxide)/polylactide composite electrospun nanofibers as a local chemotherapy system against cervical cancer in mice via vaginal implantation. The nanofibers were proven to have good mucoadhesive property by in vitro mucoadhesion test and in vivo vaginal retention evaluation. An orthotopic cervical/vaginal cancer model was established by injecting murine cervical cancer U14 cells into the vaginal submucosa nearby the cervix. By inserting the nanofibers mat into the vagina of mice, the cisplatin released from the fiber-mat showed a much more accumulation in the vagina/cervix region than in the peripheral organs such as kidneys, liver, or blood, in contrary to the case of intravenous (i.v) injection. The in vivo trials showed that a better balance between anti-tumor efficacy and systemic safety was achieved in nanofibers group than that in i.v injection group at the equal drug dose. Therefore, electrospun nanofibers present a promising approach to the local drug delivery via vagina against cervical cancer.

Electrospinning of polymeric nanofibers for drug delivery applications

Electrospinning has been recognized as a simple and versatile method for fabrication of polymer nanofibers. Various polymers that include synthetic, natural, and hybrid materials have been successfully electrospun into ultrafine fibers. The inherently high surface to volume ratio of electrospun fibers can enhance cell attachment, drug loading, and mass transfer properties. Drugs ranging from antibiotics and anticancer agents to proteins, DNA, RNA, living cells, and various growth factors have been incorporated into electrospun fibers. This article presents an overview of electrospinning techniques and their application in drug delivery.

Magnetic resonance imaging appearance and changes on intracavitary Gliadel wafer placement: A pilot study

AIM: To investigate changes on magnetic resonance imaging (MRI) which occur with intracavitary Gliadel wafer placement in patients with glioblastoma multiforme (GBM).

METHODS: This retrospective Health Insurance Portability and Accountability Act-compliant study was approved by the institutional review board, with a waiver of informed consent. A total of eight patients aged 29-67 years with GBM underwent Gliadel wafer placement. T2-weighted/FLAIR images and post-contrast T1-weighted images both before and after wafer placement were retrospectively reviewed in consensus to determine changes in the following parameters: appearance of the pericavitary tissue, pattern of tumor recurrence or progression and appearance of the Gliadel wafer itself.

RESULTS: Five out of the eight patients had a progressive increase in enhancement and pericavitary T2/ FLAIR hyperintensity within the first 2 mo and a subsequent decrease in these MRI findings. None of these patients had tumor recurrence within the first 6 mo. Three out of the eight patients demonstrated a progressive increase in enhancement and pericavitary T2 hyperintensity, which continued after the first 6 mo, and were subsequently diagnosed with true tumor progression. There was no increase in distant/nonlocal tumor recurrence. The Gliadel wafer appearance changed over time.

CONCLUSION: Pseudoprogression is common after intracavitary Gliadel wafer placement and thus care should be taken before diagnosing tumor progression or recurrence within the first 2 mo.