Drug retention and distribution after intratumoral chemotherapy with fluorouracil/epinephrine injectable gel in human pancreatic cancer xenografts

Tissue-reactive drugs enable materials-free local depots

Local, sustained drug delivery of potent therapeutics holds promise for the treatment of a myriad of localized diseases while eliminating systemic side effects. However, introduction of drug delivery depots such as viscous hydrogels or polymer-based implants is highly limited in stiff tissues such as desmoplastic tumors. Here, we present a method to create materials-free intratumoral drug depots through Tissue-Reactive Anchoring Pharmaceuticals (TRAPs). TRAPs diffuse into tissue and attach locally for sustained drug release. In TRAPs, potent drugs are modified with ECM-reactive groups and then locally injected to quickly react with accessible amines within the ECM, creating local drug depots. We demonstrate that locally injected TRAPs create dispersed, stable intratumoral depots deep within mouse and human pancreatic tumor tissues. TRAPs depots based on ECM-reactive paclitaxel (TRAP paclitaxel) had better solubility than free paclitaxel and enabled sustained in vitro and in vivo drug release. TRAP paclitaxel induced higher tumoral apoptosis and sustained better antitumor efficacy than the free drug. By providing continuous drug access to tumor cells, this material-free approach to sustained drug delivery of potent therapeutics has the potential in a wide variety of diseases where current injectable depots fall short.

Enhancing oncolytic virotherapy: Observations from a Voronoi Cell-Based model

Oncolytic virotherapy is a promising cancer treatment using genetically modified viruses. Unfortunately, virus particles rapidly decay inside the body, significantly hindering their efficacy. In this article, treatment perturbations that could overcome obstacles to oncolytic virotherapy are investigated through the development of a Voronoi Cell-Based model (VCBM). The VCBM derived captures the interaction between an oncolytic virus and cancer cells in a 2-dimensional setting by using an agent-based model, where cell edges are designated by a Voronoi tessellation. Here, we investigate the sensitivity of treatment efficacy to the configuration of the treatment injections for different tumour shapes: circular, rectangular and irregular. The model predicts that multiple off-centre injections improve treatment efficacy irrespective of tumour shape. Additionally, we investigate delaying the infection of cancer cells by modifying viral particles with a substance such as alginate (a hydrogel polymer used in a range of cancer treatments). Simulations of the VCBM show that delaying the infection of cancer cells, and thus allowing more time for virus dissemination, can improve the efficacy of oncolytic virotherapy. The simulated treatment noticeably decreases the tumour size with no increase in toxicity. Improving oncolytic virotherapy in this way allows for a more effective treatment without changing its fundamental essence.

Drug Delivery Strategies for Platinum-Based Chemotherapy

Few chemotherapeutics have had such an impact on cancer management as cis-diamminedichloridoplatinum(II) (CDDP), also known as cisplatin. The first member of the platinum-based drug family, CDDP's potent toxicity in disrupting DNA replication has led to its widespread use in multidrug therapies, with particular benefit in patients with testicular cancers. However, CDDP also produces significant side effects that limit the maximum systemic dose. Various strategies have been developed to address this challenge including encapsulation within micro- or nanocarriers and the use of external stimuli such as ultrasound to promote uptake and release. The aim of this review is to look at these strategies and recent scientific and clinical developments.

Drug coated microneedles for minimally-invasive treatment of oral carcinomas: development and in vitro evaluation

Treatment of recurring oral cancers is challenging as common surgical approaches are not feasible for these patients. In addition, these patients do not respond well to systemic chemotherapy. Localized intratumoral injection of anti-cancer drugs is considered to be an attractive alternative treatment approach for these patients. However, conventional hypodermic injections result in poor distribution of the drug in the tumor and leakage of the drug from the injection site to systemic circulation, in addition to causing pain to the patient. The objective of this study was to develop coated microneedles as a novel device for direct and minimally invasive intratumoral delivery of anti-cancer drugs. Poly(lactic-co-glycolic) acid (PLGA) nanoparticles encapsulating doxorubicin (DOX) were prepared and coated on inplane (1D) microneedles. Microscopic evaluation of 3D tissue phantoms and porcine cadaver buccal tissues that were treated with 1D microneedle arrays coated with DOX-PLGA nanoparticles demonstrated that DOX could diffuse both laterally and vertically in to the tissues and produced cellular cytotoxicity. Out of plane (2D) microneedle arrays measuring 1 cm x 1 cm with 57 microneedles coated with free DOX could produce uniform distribution of DOX in a porcine cadaver buccal tissue up to a depth greater than 3 mm. Hypodermic injection of different volumes in to a porcine buccal tissue confirmed significant leakage of the injected volume (about 25% of the injected 80 μl). In summary, this study demonstrates that drug coated microneedles is an attractive microscale device that can uniformly and effectively deliver drugs to localized oral cancers. This microscale device has potential to impact the treatment of oral cancer patients.

Fe3+-induced bioinspired chitosan hydrogels for the sustained and controlled release of doxorubicin

A novel Fe³⁺-induced mussel-inspired CCS–NACCS hydrogel was developed for the sustained and controlled release of doxorubicin (DOX).

Novel curcumin-loaded magnetic nanoparticles for pancreatic cancer treatment

Curcumin (CUR), a naturally occurring polyphenol derived from the root of Curcuma longa, has showed potent anticancer and cancer prevention activity in a variety of cancers. However, the clinical translation of CUR has been significantly hampered due to its extensive degradation, suboptimal pharmacokinetics, and poor bioavailability. To address these clinically relevant issues, we have developed a novel CUR-loaded magnetic nanoparticle (MNP-CUR) formulation. Herein, we have evaluated the in vitro and in vivo therapeutic efficacy of this novel MNP-CUR formulation in pancreatic cancer. Human pancreatic cancer cells (HPAF-II and Panc-1) exhibited efficient internalization of the MNP-CUR formulation in a dose-dependent manner. As a result, the MNP-CUR formulation effectively inhibited growth of HPAF-II and Panc-1 cells in cell proliferation and colony formation assays. The MNP-CUR formulation suppressed pancreatic tumor growth in an HPAF-II xenograft mouse model and improved the survival of mice by delaying tumor growth. The growth-inhibitory effect of MNP-CUR formulation correlated with the suppression of proliferating cell nuclear antigen (PCNA), B-cell lymphoma-extra large (Bcl-xL), induced myeloid leukemia cell differentiation protein (Mcl-1), cell surface-associated Mucin 1 (MUC1), collagen I, and enhanced membrane β-catenin expression. MNP-CUR formulation did not show any sign of hemotoxicity and was stable after incubation with human serum proteins. In addition, the MNP-CUR formulation improved serum bioavailability of CUR in mice up to 2.5-fold as compared with free CUR. Biodistribution studies show that a significant amount of MNP-CUR formulation was able to reach the pancreatic xenograft tumor(s), which suggests its clinical translational potential. In conclusion, this study suggests that our novel MNP-CUR formulation can be valuable for the treatment of pancreatic cancer.

Effect of viscous additives on the absorption and hepatic disposition of 5-fluorouracil (5-FU) after application to liver surface in rats

Objectives  The aim was to study the effect of viscous additives on the absorption and hepatic disposition of 5-fluorouracil (5-FU) after application to the liver surface in rats. Methods  5-FU solution with or without viscous additives was applied to the rat liver surface with a cylindrical diffusion cell. Then, blood and the remaining solution in the diffusion cell were collected at selected times, followed by excision of the liver. The excised liver was divided into three sites and assayed for 5-FU content. Key findings  The absorption rate of 5-FU from the liver surface was decreased in the presence of carboxymethylcellulose sodium (CMC-Na) and polyvinyl alcohol (PVA) as compared with the control. The k(a) values of PVA 15% and CMC-Na 1% were reduced to about 80 and 67% of the control. The maximum plasma concentration of 5-FU was decreased by incorporation of viscous additives. The 5-FU concentration at the diffusion cell attachment site of the liver (site 1) plateaued at 180 min in the absence of viscous additives. On the other hand, the concentration of 5-FU at site 1 increased in a time-dependent manner until 360 min in the presence of viscous additives. Conclusion  Viscous additives might be useful for retaining drugs at their application site and controlling the rate of absorption from the liver surface.

Combined Tumor Therapy by Using Radiofrequency Ablation and 5-FU–Laden Polymer Implants: Evaluation in Rats and Rabbits

PURPOSE

To evaluate the use of 5-fluorouracil (5-FU)-laden polymer implants as an adjunct to radiofrequency (RF) ablation for tumor treatment.

MATERIALS AND METHODS

All animal studies were performed in compliance with the Case Western Reserve University Institutional Animal Care and Use Committee guidelines. Three studies were performed to investigate (a) in vitro dissolution of 5-FU-laden polymer implants in saline and bovine serum, (b) tissue distribution of 5-FU and its metabolite, 5-fluorouridine (5-FUrd), in the ablated liver tissue of rats (n = 4), and (c) efficacy of combined approach (n = 4) compared with that of ablation alone (n = 6) for VX2 liver tumor model in rabbits. Characterization of 5-FU release in vitro and distribution of 5-FU in rat liver tissue were analyzed by using high performance liquid chromatography; in vivo efficacy was assessed by using computed tomography and pathologic examination.

RESULTS

Results of the in vitro dissolution study showed that a 75% release of 5-FU occurred in 2 days when exposed to bovine serum and in 9 days when exposed to phosphate-buffered saline. In the ablated rat liver, the 5-FU level was higher at the center and lower at the periphery of the tissue both at 24 hours (41.0 mg per kilogram tissue vs 15.0 mg per kilogram tissue, respectively) and at 48 hours (8.0 mg per kilogram tissue vs 2.0 mg per kilogram tissue, respectively). The 5-FUrd concentration was twofold higher peripherally than centrally and was higher at 48 hours than at 24 hours. In rabbits, local delivery of 5-FU immediately after RF ablation provided a significant (P < .05) reduction in tumor size compared with ablation alone (1.80 cm3 +/- 0.28 [standard error] vs 3.53 cm3 +/- 0.52, respectively; P = .034) and a more than 20-fold reduction in tumor size compared with the control (1.80 cm3 +/- 0.28 vs 41.95 cm3 +/- 11.58, respectively; P = .018).

CONCLUSION

Combined treatment by using 5-FU polymer implants and RF ablation shows uniform sustained release of 5-FU for 48 hours at least 8 mm from the edge of the ablation zone and appears to be successful at controlling the growth of an experimental tumor in rabbits appreciably better than does ablation alone.

Intralesional chemotherapy for head and neck carcinoma: a review of the literature

In the last decade chemotherapy has gained widespread acceptance in the treatment of oral and pharyngeal cancer. Current standard treatment for advanced lesions consists of concomitant radiation and chemotherapy. This approach has provided marginal improvement of prognosis for Stage III-IV disease. Recent studies have explored the idea that locally delivered cytotoxic drugs could further improve prognosis in this patient population. We review this literature with the objective of popularizing these data and suggesting future directions for treatment and clinical research for head and neck cancer.

Intratumoral NAMI-A treatment triggers metastasis reduction, which correlates to CD44 regulation and tumor infiltrating lymphocyte recruitment

Intratumor (i.t.) injection of 35 mg/kg/day NAMI-A for six consecutive days to CBA mice bearing i.m. implants of MCa mammary carcinoma reduces primary tumor growth and particularly lung metastasis formation, causing 60% of animals to be free of macroscopically detectable metastases. The i.t. treatment allows study of the effects of NAMI-A on in vivo tumor cells exposed to millimolar concentrations for a relatively prolonged time. Under these conditions, NAMI-A reduces the number of CD44+ tumor cells and changes tumor cell phenotype to a lower aggressive behavior, as shown by scanning electron microscopy analysis. On primary tumor site, NAMI-A causes unbalance between 2n and aneuploid cells in favor of lymphocytes. Furthermore, in tumor tissue, nitric oxide production is increased and active matrix metalloproteinase 9 is decreased, and these effects are accompanied by a reduced hemoglobin concentration. These data are in agreement with the reduction of tumor invasion and metastasis and suggest the therapeutic usefulness of NAMI-A in neoadjuvant or tumor reduction treatments for preventing metastasis formation. These data further stress the usefulness of intratumor treatments as experimental preclinical model for studying in vivo the mechanism of tumor cell interactions after prolonged exposure to ruthenium-based compounds to be developed for metastasis inhibition.

Toxicities and therapeutic effect of 5-fluorouracil controlled release implant on tumor-bearing rats

AIM: To investigate the toxicities, biodistribution and anticancer effect of 5-fluorouracil controlled release implant (5-FUCI) on Walker 256 carcinosarcoma cells in Wistar rats.

METHODS: Experiment 1: Wistar rats were randomly divided into three groups (27 rats per group). Blank implant was implanted in left lobe of the liver, and rats were treated with saline solution (in group A) or 5-fluorouracil (subcutaneous injection, group B). 5-FUCI was inserted in left lobe of the liver (group C). The gastrointestinal and hematological toxicities were observed and contents of element F in group C were assayed. Experiment 2: on day 6 after Walker-256 carcinosarcoma transplantation in left lobe of the liver, 5-FUCI was implanted in right lobe of the liver (group E) or left lobe (group F), and rats in control group (group D) were inserted blank implant. Tumor inhibition rate and survival time were investigated.

RESULTS: 5-FUCI showed no obvious toxic effect, extraction of Evan’s blue from gastrointestinal tissue was normal, the peripheral white blood cells and bone marrow nucleated cells were not reduced, compared with control group (P > 0.05). Histological examination revealed that there were no visible changes in small intestinal mucosa, The concentration of 5-fluorouracil in left lobe of the liver was 9.84, 28, 34 times as much as those of right lobe of the liver, heart and kidney respectively after the implantation in group C. They kept a high level of fluorouracil in left lobe of the liver, ranging from (4.414% ± 0.482%) to (7.800% ± 0.804%), for eight weeks. Survival days were 28.0 ± 2.2, 30.0 ± 3.2 and 38.7 ± 6.7 d in group D, E and F, respectively.

CONCLUSION: 5-FUCI shows no obvious toxicities to gastrointestinal tract and myelotoxicity. After implantation, it kept a high level of 5- fluorouracil in surrounding tissues of the implant for eight weeks. Its antitumor effect on Walker-256 carcinosarcoma is demonstrated.

Recent progress in drug delivery systems for anticancer agents

Recent progress in understanding the molecular basis of cancer brought out new materials such as oligonucleotides, genes, peptides and proteins as a source of new anticancer agents. Due to their macromolecular properties, however, new strategies of delivery for them are required to achieve their full therapeutic efficacy in clinical setting. Development of improved dosage forms of currently marketed anticancer drugs can also enhance their therapeutic values. Currently developed delivery systems for anticancer agents include colloidal systems (liposomes, emulsions, nanoparticles and micelles), polymer implants and polymer conjugates. These delivery systems have been able to provide enhanced therapeutic activity and reduced toxicity of anticancer agents mainly by altering their pharmacokinetics and biodistribution. Furthermore, the identification of cell-specific receptor/antigens on cancer cells have brought the development of ligand- or antibody-bearing delivery systems which can be targeted to cancer cells by specific binding to receptors or antigens. They have exhibited specific and selective delivery of anticancer agents to cancer. As a consequence of extensive research, clinical development of anticancer agents utilizing various delivery systems is undergoing worldwide. New technologies and multidisciplinary expertise to develop advanced drug delivery systems, applicable to a wide range of anticancer agents, may eventually lead to an effective cancer therapy in the future.

Intratumoral cancer chemotherapy and immunotherapy: opportunities for nonsystemic preoperative drug delivery

The recent literature documents the growing interest in local intratumoral chemotherapy as well as systemic preoperative chemotherapy with evidence for improved outcomes using these therapeutic modalities. Nevertheless, with few exceptions, the conventional wisdom and standard of care for clinical and surgical oncology remains surgery followed by radiation and/or systemic chemotherapy, as deemed appropriate based on clinical findings. This, in spite of the fact that the toxicity of conventional systemic chemotherapy and immunotherapy affords limited effectiveness and frequently compromises the quality of life for patients. Indeed, with systemic chemotherapy, the oncologist (and the patient) often walks a fine line between attempting tumour remission with prolonged survival and damaging the patient's vital functions to the point of death. In this context, it has probably been obvious for more than 100 years, due in part to the pioneering work of Ehrlich (1878), that targeted or localized drug delivery should be a major goal of chemotherapy. However, there is still only limited clinical use of nonsystemic intratumoral chemotherapy for even those high mortality cancers which are characterized by well defined primary lesions i.e. breast, colorectal, lung, prostate, and skin. There has been a proliferation of intratumoral chemotherapy and immunotherapy research during the past two to three years. It is therefore the objective of this review to focus much more attention upon intratumoral therapeutic concepts which could limit adverse systemic events and which might combine clinically feasible methods for localized preoperative chemotherapy and/or immunotherapy with surgery. Since our review of intratumoral chemoimmunotherapy almost 20 years ago (McLaughlin & Goldberg 1983), there have been few comprehensive reviews of this field; only one of broad scope (Brincker 1993), three devoted specifically to gliomas (Tomita 1991; Walter et al. 1995; Haroun & Brem 2000), one on hepatomas (Venook 2000), one concerning veterinary applications (Theon 1998), and one older review of dermatological applications (Goette 1981). However, none have shed light on practical opportunities for combining intratumoral therapy with subsequent surgical resection. Given the state-of-the-art in clinical and surgical oncology, and the advances that have been made in intratumoral drug delivery, minimally invasive tumour access i.e. fine needle biopsy, new drugs and drug delivery systems, and preoperative chemotherapy, it is timely to present a review of studies which may suggest future opportunities for safer, more effective, and clinically practical non-systemic therapy.