A phase I study of intraperitoneal nanoparticulate paclitaxel (Nanotax®) in patients with peritoneal malignancies

Innovative landscapes in intraperitoneal therapy of ovarian cancer

Epithelial ovarian cancer is the most prevalent gynecological malignancy, characterized by high mortality rates due to its late-stage diagnosis and frequent recurrence. The current standard of care for ovarian cancer is a combination of debulking surgery followed by the conventional mode of chemotherapy. Despite significant advances in therapeutic modalities, the overall survival rate of EOC continues to be poor, mainly because low concentrations of the chemotherapeutics reach the peritoneum, which is the primary site of ovarian cancer, leading to disease relapse. Here, intraperitoneal chemotherapy gains advantage due to its ability to deliver the drug molecules directly to the peritoneal cavity and provide localized and sustained effects. This is facilitated by the use of diverse kinds of nano or micron sized delivery systems, which help in transporting drugs, vaccines, antibodies and genes appropriately to the peritoneum for its desired function. This review article delves on how intraperitoneal delivery impacts the therapy of epithelial ovarian cancer spanning the conventional therapeutic modes to the recent nanoinnovations in chemotherapy, immunotherapy and gene therapy.

A Clinical Pharmacological Perspective on Intraperitoneal Chemotherapy

Peritoneal metastases (PM), frequently observed in malignancies such as ovarian, colorectal, pancreatic, and gastric cancers, present a significant therapeutic challenge due to poor prognosis and limited effectiveness to systemic chemotherapy. The peritoneal-plasma barrier reduces effective drug transfer from plasma to the peritoneal cavity, reducing cytotoxic effects on PM. Intraperitoneal (IP) chemotherapy offers a locoregional approach, enabling high local drug concentrations that can enhance therapeutic efficacy while limiting systemic toxicity. The three major methods for IP administration-hyperthermic intraperitoneal chemotherapy (HIPEC), pressurized intraperitoneal aerosol chemotherapy (PIPAC), and catheter-based IP (CBIP) chemotherapy-each provide unique pharmacokinetic (PK) advantages for PM treatment. This review provides a comprehensive update on the pharmacological rationale of IP chemotherapy, focusing on drug characteristics that support extended IP retention and effective tumor targeting. The effects of administration variables are discussed, highlighting their role in optimizing IP drug exposure. Additionally, recent PK data on commonly used drugs in IP therapy, including platinum-based agents, taxanes, and novel nanoparticle formulations, will be evaluated. While PK rationale supports the administration of IP chemotherapy, further efficacy results from ongoing clinical trials are still awaited. Innovations in nanoparticle-based formulations and controlled-release systems offer substantial potential for improving both drug retention and targeted delivery, enhancing treatment precision and minimizing systemic toxicity. Continued exploration in these areas, along with optimization of IP administration protocols, is vital for advancing patient outcomes, refining therapeutic strategies, and maximizing the benefits of IP chemotherapy in clinical practice.

Nanomicellar Prodrug Delivery of Glucose-Paclitaxel: A Strategy to Mitigate Paclitaxel Toxicity

Background

Paclitaxel-induced blood system disorders and peripheral neuropathy impede the progress of new formulations in clinical trials.

Purpose of Study

To mitigate these adverse effects by developing and validating a prodrug strategy that encapsulates a glucose-paclitaxel conjugate within nanomicelles.

Material and Methods

Succinic anhydride was used as a bridge to couple C2'-paclitaxel with methyl 2'-glucopyranose and prepare a glucose-paclitaxel conjugate. Nanomicelles were prepared via solid-phase dispersion, and dynamic light scattering was used to determine their average diameter and the polydispersity index. High-performance liquid chromatography (HPLC) was employed to evaluate drug-loading capacity and encapsulation efficiency. Pharmacokinetic studies and in vivo toxicity assays were performed in Sprague-Dawley (SD) rats.

Results

The nanomicellar product exhibited a spherical shape with a particle size distribution between 20-60 nm, a PDI of 0.26 ± 0.01, and an encapsulation efficiency of 95.59 ± 1.73%. The pharmacokinetic profile of glucose-paclitaxel nanomicelles in SD rats was markedly different from that of the paclitaxel solution group. Notably, the plasma drug concentration of glucose-paclitaxel nanomicelles was significantly higher than the paclitaxel solution 15 minutes post-administration, with a Vz at only 40% of that of the paclitaxel solution, while the AUC0-∞ was five times greater than that of the paclitaxel solution. Ultimately, glucose-paclitaxel nanomicelles effectively alleviated blood system disorders and peripheral neuropathy in SD rats.

Conclusion

The encapsulation of glucose-paclitaxel conjugates within nanomicelles presents a viable solution to the dose-limiting toxicities associated with paclitaxel, offering new perspectives on safety for the development of paclitaxel-based therapeutics.

Nanotheranostics for gynecological cancers: a path forward for Africa

Nanoparticle-based therapies represent a transformative approach to managing gynecological cancers, offering targeted treatment strategies that minimize harm to healthy tissues while maximizing therapeutic efficacy. Despite their potential, implementing these advanced treatments in Africa is needed by a complex interplay of technological, economic, regulatory, and ethical challenges. This paper examines the current landscape of nanoparticle-based therapies, identifying critical barriers to their adoption, including inadequate infrastructure, high costs, and insufficient regulatory frameworks. Technological deficiencies manifest as a need for advanced nanoparticle synthesis, delivery, and diagnostics equipment, impeding research and clinical applications. Economically, the high production costs of nanoparticles, compounded by limited access to advanced diagnostic and treatment facilities, create significant financial barriers for healthcare systems and patients alike. Additionally, the regulatory environment needs to be more cohesive, characterized by a lack of established protocols and expertise to evaluate the unique properties of nanomedicines. However, opportunities for advancement exist through focused research and development initiatives. Targeted drug delivery systems, early detection methods, and immunotherapy integration are promising avenues to enhance treatment outcomes. Collaborative partnerships between African institutions and international research entities, alongside public-private collaborations, could bolster local capabilities in nanomedicine. To facilitate the integration of nanoparticle-based therapies, African governments must prioritize funding for nanomedicine research, create robust regulatory frameworks, and ensure equitable access to these innovative treatments. A concerted effort involving policy reforms, investment, and collaboration is essential for overcoming existing barriers and realizing the full potential of nanoparticle-based therapies in improving health outcomes for gynecological cancer patients across Africa.

The journey of nanoparticles in the abdominal cavity: Exploring their in vivo fate and impact factors

Peritoneal carcinomatosis (PC) is caused by metastasis of primary tumor cells from intra-abdominal organs to the peritoneal surface. Intraperitoneal (IP) chemotherapy allows close contact of high concentrations of therapeutic agents with cancer cells in the peritoneal cavity to prolong patient survival. However, conventional IP chemotherapy is prone to rapid elimination from the peritoneal cavity and lacks specificity towards cancer cells. To address these challenges, there is an imperative demand for exploiting novel drug delivery systems to enhance drug retention in the peritoneal cavity and target PC cells. Therefore, in this review, we first recapitulate the physiological structures and barriers associated with IP drug delivery, highlighting the in vivo fate of nanoparticles (NPs) after IP administration. Furthermore, the influence of physicochemical properties (particle size, charge, surface modification, and carrier composition) on the in vivo fate of NPs is discussed. Perspectives on the rational design of NPs for IP therapy and recent clinical progress are also provided.

Size-dependent translocation and lymphatic transportation of polymeric nanocarriers post intraperitoneal administration

Intraperitoneal (i.p.) administered nanomedicine has been widely applied in the clinical treatment of intra-abdominal diseases and preclinical pharmacological investigations. However, current understandings about the in vivo fate of i.p.-administered drug remains controversial owing to lack of reliable investigation tools. This work presents a nanoparticle-labeling strategy based on aggregation-caused quenching (ACQ) probes in the second near-infrared (NIR-II) window, which can eliminate the interference of unbound probes and allow for non-invasive tracking of nanoparticles in deep tissues. Our results strongly evidence a size-dependent absorption and biodistribution of the i.p.-administered polymeric nanocarriers (PNs) with particle sizes ranging from 30 to 1000 nm both in vivo and ex vivo, and moreover provide a clear visualization of lymphatic transportation and lymph node retention of integral PNs. Importantly, our findings suggest that small particles (≤30 nm) are favorable in systemic therapies due to their rapid absorption and high concentration (>19 %ID mL-1) in circulation, while large particles (over 1000 nm) are meant for localized treatment of abdominal diseases. Besides, the high retention of 200 nm nanoparticles within lymph nodes indicates their promising role in cancer vaccines and lymphatic diseases including lymph node metastasis.

Biopolymer-Based Nanomedicine for Cancer Therapy: Opportunities and Challenges

Cancer, as the foremost challenge among human diseases, has plagued medical professionals for many years. While there have been numerous treatment approaches in clinical practice, they often cause additional harm to patients. The emergence of nanotechnology has brought new directions for cancer treatment, which can deliver anticancer drugs specifically to tumor areas. This article first introduces the application scenarios of nanotherapies and treatment strategies of nanomedicine. Then, the noteworthy characteristics exhibited by biopolymer materials were described, which make biopolymers stand out in polymeric nanomedicine delivery. Next, we focus on summarizing the state-of-art studies of five categories of proteins (Albumin, Gelatin, Silk fibroin, Zein, Ferritin), nine varieties of polysaccharides (Chitosan, Starch, Hyaluronic acid, Dextran, cellulose, Fucoidan, Carrageenan, Lignin, Pectin) and liposomes in the field of anticancer drug delivery. Finally, we also provide a summary of the advantages and limitations of these biopolymers, discuss the prevailing impediments to their application, and discuss in detail the prospective research directions. This review not only helps readers understand the current development status of nano anticancer drug delivery systems based on biopolymers, but also is helpful for readers to understand the properties of various biopolymers and find suitable solutions in this field through comparative reading.

Intratumoral Injection of Large Surface Area Microparticle Taxanes in Carcinomas Increases Immune Effector Cell Concentrations, Checkpoint Expression, and Synergy with Checkpoint Inhibitors: A Review of Preclinical and Clinical Studies

This review summarizes development of large surface area microparticle paclitaxel (LSAM-PTX) and docetaxel (LSAM-DTX) for local treatment of primary carcinomas with emphasis on immunomodulation. Intratumoral (IT) delivery of LSAM-PTX and LSAM-DTX provides continuous, therapeutic drug levels for several weeks. Preclinical studies and clinical trials reported a reduction in tumor volume (TV) and immunomodulation in primary tumor and peripheral blood with increases in innate and adaptive immune cells and decreases in suppressor cells. Increased levels of checkpoint expression of immune cells occurred in clinical trials of high-risk non-muscle-invasive bladder cancer (LSAM-DTX) and unresectable localized pancreatic cancer (LSAM-PTX). TV reduction and increases in immune effector cells occurred following IT LSAM-DTX and IT LSAM-PTX together with anti-mCTLA-4 and anti-mPD-1, respectively. Synergistic benefits from combinatorial therapy in a 4T1-Luc breast cancer model included reduction of metastasis with IT LSAM-DTX + anti-mCTLA-4. IT LSAM-PTX and LSAM-DTX are tumoricidal, immune enhancing, and may improve solid tumor response to immune checkpoint inhibitors without additional systemic toxicity.

Intratumoral Treatment of Melanoma Tumors with Large Surface Area Microparticle Paclitaxel and Synergy with Immune Checkpoint Inhibition

The effects of intratumoral (IT) large surface area microparticle paclitaxel (LSAM-PTX) alone and in combination with systemic administration of the programmed cell death protein antibody (anti-mPD-1) were evaluated in a syngeneic murine model of melanoma. Groups of mice with subcutaneously implanted Clone M3 (Cloudman S91) tumors were treated with single and combination therapies. Tumor volume (TV) measurements, body weights, and clinical observations were followed in-life. At end of study, tumor-site tissues were collected, measured, and processed for flow cytometry along with blood and lymph nodes. The combination of LSAM-PTX + anti-mPD-1 resulted in an antitumoral response, which produced a significant decrease in TV compared to control animals. TV decreases also occurred in the LSAM-PTX and anti-mPD-1 groups. Flow cytometry analysis found increases in granulocytes and M2 macrophages and decreases in dendritic cells (DC) and monocytic myeloid-derived suppressor cells (M-MDSC) in tumor-site tissues. Increases in granulocytes and decreases in CD4+ T cells, macrophages, and M1 macrophages were found in the blood of animals administered the combination treatment. Increases in natural killer (NK) cells were found in lymph node tissue in the combination treatment group. These findings suggest that IT LSAM-PTX may provide benefit in the local treatment of melanomas and may synergize with systemic anti-PD-1 therapy, leading to additional tumoricidal outcomes without added systemic toxicity.

A disulfiram/copper gluconate co-loaded bi-layered long-term drug delivery system for intraperitoneal treatment of peritoneal carcinomatosis

To develop a long-term drug delivery system for the treatment of primary and metastatic peritoneal carcinoma (PC) by intraperitoneal (IP) injection, a disulfiram (DSF)/copper gluconate (Cu-Glu)-co-loaded bi-layered poly (lactic acid-coglycolic acid) (PLGA) microspheres (Ms) - thermosensitive hydrogel system (DSF-Ms-Cu-Glu-Gel) was established. Rate and mechanisms of drug release from DSF-Ms-Cu-Glu-Gel were explored. The anti-tumor effects of DSF-Ms-Cu-Glu-Gel by IP injection were evaluated using H22 xenograft tumor model mice. The accumulative release of DSF from Ms on the 10th day was 83.79% without burst release. When Ms were dispersed into B-Gel, burst release at 24 h decreased to 14.63%. The results showed that bis (diethyldithiocarbamate)-copper (Cu(DDC)2) was formed in DSF-Ms-Cu-Glu-Gel and slowly released from B-Gel. In a pharmacodynamic study, the mount of tumor nodes and ascitic fluid decreased in the DSF-Ms-Cu-Glu-Gel group. This was because: (1) DSF-Ms-Cu-Glu-Gel system co-loaded DSF and Cu-Glu, and physically isolated DSF and Cu-Glu before injection to protect DSF; (2) space and water were provided for the formation of Cu(DDC)2; (3) could provide an effective drug concentration in the abdominal cavity for a long time; (4) both DSF and Cu(DDC)2 were effective anti-tumor drugs, and the formation of Cu(DDC)2 occurred in the abdominal cavity, which further enhanced the anti-tumor activity. Thus, the DSF-Ms-Cu-Glu-Gel system can be potentially used for the IP treatment of PC in the future.

Surgical management of peritoneal metastasis: Opportunities for pharmaceutical research

Cytoreductive surgery (CRS) has emerged as a survival-extending treatment of peritoneal metastasis (PM); recent advances include using intraperitoneal chemotherapy (IPC) at normothermic or hyperthermic temperatures, or under pressure (CRS + IPC). Clinical CRS + IPC research has established its highly variable efficacy and suggested tumor size, tumor locations and presence of ascites as potential determinants. On the other hand, there is limited knowledge on the effects of pharmaceutical properties on treatment outcomes. The present study investigated the inter-subject variability of paclitaxel binding to proteins in patient ascites because some PM patients show accumulation of ascites and because activity and transport of highly protein-bound drugs such as paclitaxel are affected by protein binding. Ascites samples were collected from 26 patients and investigated for their protein contents using LC/MS/MS proteomics analysis and for the concentrations of total proteins and two major paclitaxel-binding proteins (human serum albumin or HSA and α-1-acid glycoprotein or AAG). The association constants of paclitaxel to HSA and AAG and the extent of protein binding of paclitaxel in patient ascites were studied using equilibrium dialysis. Proteomic analysis of four randomly selected samples revealed 288 proteins, >90% of which are also present in human plasma. Between 72% - 94% of paclitaxel was bound to proteins in patient ascites. The concentrations of HSA and AAG in ascites showed substantial inter-subject variations, ranging from 14.7 - 46.3 mg/mL and 0.13-2.56 mg/mL, respectively. The respective paclitaxel association constants to commercially available HSA and AAG were ∼ 3.5 and ∼ 120 mM. Calculation using these constants and the HSA and AAG concentrations in individual patient ascites indicated that these two proteins accounted for >85% of the total protein-binding of paclitaxel in ascites. The extensive drug binding to ascites proteins, by reducing the pharmacologically active free fraction, may lead to the diminished CRS efficacy in PM patients with ascites. Clinical advances in CRS + IPC have outpaced current knowledge of pharmaceutical properties in this setting. IPC, as a locally acting therapy, is subjected to processes different from those governing systemic treatments. This study, to our knowledge, is the first to illustrate the implications of drug properties in the CRS + IPC efficacy against PM. While drugs are now an integral part of PM patient management, there is limited pharmaceutical research in this treatment setting (e.g., effects of hyperthermia or pressure on drug transport or release from delivery systems, pharmacokinetics, pharmacodynamics). Hence, CRS + IPC of PM represents an area where additional pharmaceutical research can assist further development and optimization.

The interplay between PEGylated nanoparticles and blood immune system

During the last two decades, an increasing number of reports have pointed out that the immunogenicity of polyethylene glycol (PEG) may trigger accelerated blood clearance (ABC) and hypersensitivity reaction (HSR) to PEGylated nanoparticles, which could make PEG modification counterproductive. These phenomena would be detrimental to the efficacy of the load and even life-threatening to patients. Consequently, further elucidation of the interplay between PEGylated nanoparticles and the blood immune system will be beneficial to developing and applying related formulations. Many groups have worked to unveil the relevance of structural factors, dosing schedule, and other factors to the ABC phenomenon and hypersensitivity reaction. Interestingly, the results of some reports seem to be difficult to interpret or contradict with other reports. In this review, we summarize the physiological mechanisms of PEG-specific immune response. Moreover, we speculate on the potential relationship between the induction phase and the effectuation phase to explain the divergent results in published reports. In addition, the role of nanoparticle-associated factors is discussed based on the classification of the action phase. This review may help researchers to develop PEGylated nanoparticles to avoid unfavorable immune responses based on the underlying mechanism.

Localized chemotherapy approaches and advanced drug delivery strategies: a step forward in the treatment of peritoneal carcinomatosis from ovarian cancer

Peritoneal carcinomatosis (PC) is a common outcome of epithelial ovarian carcinoma and is the leading cause of death for these patients. Tumor location, extent, peculiarities of the microenvironment, and the development of drug resistance are the main challenges that need to be addressed to improve therapeutic outcome. The development of new procedures such as HIPEC (Hyperthermic Intraperitoneal Chemotherapy) and PIPAC (Pressurized Intraperitoneal Aerosol Chemotherapy) have enabled locoregional delivery of chemotherapeutics, while the increasingly efficient design and development of advanced drug delivery micro and nanosystems are helping to promote tumor targeting and penetration and to reduce the side effects associated with systemic chemotherapy administration. The possibility of combining drug-loaded carriers with delivery via HIPEC and PIPAC represents a powerful tool to improve treatment efficacy, and this possibility has recently begun to be explored. This review will discuss the latest advances in the treatment of PC derived from ovarian cancer, with a focus on the potential of PIPAC and nanoparticles in terms of their application to develop new therapeutic strategies and future prospects.

Response of Locally Advanced Pancreatic Cancer to Intratumoral Injection of Large Surface Area Microparticle Paclitaxel: Initial Report of Safety and Clinical Outcome

OBJECTIVES

Large surface area microparticle paclitaxel (LSAM-PTX) provides an intratumoral (IT) chemotherapeutic depot. Safety, tolerability, and tumor response to IT LSAM-PTX delivered by endoscopic ultrasound-fine needle injection were evaluated in subjects with unresectable locally advanced pancreatic cancer (LAPC).

METHODS

Ten subjects treated in a dose escalation phase and 22 additional subjects receiving 2 injections, 4 weeks apart, of 15 mg/mL LSAM-PTX were followed for 12 months. Paclitaxel pharmacokinetics were evaluated, imaging at 3 and 6 months determined tumor response, and multiplex immunofluorescence was conducted to characterize local immune response.

RESULTS

Most treatment-emergent adverse events were attributed to LAPC. Plasma paclitaxel levels were negligible. Eight subjects' tumors became resectable after IT LSAM-PTX, and 5 of 6 (83%) were resected with R0. Multiplex immunofluorescence of resected tumors demonstrated increased T cells, natural killer cells, and macrophages and decreased myeloid-derived suppressor cells. Six-month disease control rate was 94%, and median overall survival was 19.7 months in the 2-injection subjects. For nonresected and resected groups, overall survival times were 18.9 and 35.2 months, respectively.

CONCLUSIONS

Neoadjuvant IT LSAM-PTX, in combination with SOC, was well tolerated and may provide benefits to LAPC patients, evidenced by enhanced immune response, improved disease control rate, restaging leading to surgery, and extended survival.

Local administration of large surface area microparticle docetaxel to solid carcinomas induces direct cytotoxicity and immune-mediated tumoricidal effects: preclinical and clinical studies

This report describes local administration of large surface area microparticle docetaxel (LSAM-DTX: ~ 3.5- to 7.5-µm-sized particles with high relative surface area) in preclinical oncology models and in a clinical trial in urothelial carcinoma. Reductions in tumor volumes were found following intratumoral (IT) injection of LSAM-DTX into human urologic carcinoma cell lines and syngeneic murine renal and breast cancer cell lines. Compared to IT injections of docetaxel solution typically administered intravenously, IT LSAM-DTX results in 40-fold more docetaxel retained within the tumor. The long residence time of LSAM-DTX within the tumor acts as a drug depot, allowing for continuous release of docetaxel, exposing tumor cells to high, therapeutic levels of chemotherapeutic for several weeks. Local LSAM-DTX results in tumoricidal effects at the site of deposition as well as in distant tumors, and IT LSAM-DTX in combination with immune checkpoint inhibitor therapy reduces or eliminates metastatic spread. Tumoricidal effects of local LSAM-DTX are accompanied by immunomodulation including increases in innate and adaptive immune cells in the tumor microenvironment and peripheral blood. Encouraging clinical results indicate that local administration of LSAM-DTX may provide therapeutic benefits for non-muscle invasive bladder cancer and muscle invasive bladder cancer patients; treatments were well-tolerated with few local and systemic adverse events and negligible systemic docetaxel exposure. Results of preclinical and clinical investigations summarized here indicate that local administration of LSAM-DTX may augment tumor response to systemically administered chemotherapy, targeted therapy, or immunotherapy without contributing to systemic toxicity.

A Review of Endoscopic Ultrasound-Guided Chemoablative Techniques for Pancreatic Cystic Lesions

Pancreatic cystic lesions (PCLs) are known precursors to pancreatic cancer, one of the deadliest types of cancer worldwide. Surgical removal or pancreatectomies remain the central approach to managing precancerous high-risk PCLs. Endoscopic ultrasound (EUS)-guided therapeutic management of PCLs is a novel management strategy for patients with prohibitive surgical risks. Various ablation techniques have been explored in previous studies utilizing EUS-guided fine needle injection (FNI) of alcohol and chemotherapeutic agents. This review article focuses on EUS-FNI and chemoablation, encompassing the evolution of chemoablation, pancreatic cyst selection, chemotherapy drug selection, including novel agents, and a discussion of its safety and efficacy.

Application of intraperitoneal hyperthermic perfusion chemotherapy in gastric cancer

Gastric cancer is one of the most common malignant tumors in China. Intraperitoneal hyperthermic perfusion chemotherapy is a comprehensive therapy that combines intraperitoneal perfusion, hyperthermia, and chemotherapy. It has a good curative effect in peritoneal metastasis of gastric cancer. In recent years, with the continuous progress of technology and the deepening of research, the scope of application of intraperitoneal hyperthermic perfusion chemotherapy is more extensive. In this paper, we discuss intraperitoneal hyperthermic perfusion chemotherapy with regard to its application in gastric cancer, commonly used drugs, safety, and prospects.

Advances in Polymeric Colloids for Cancer Treatment

Polymer colloids have remarkable features and are gaining importance in many areas of research including medicinal science. Presently, the innovation of cancer drugs is at the top in the world. Polymer colloids have been used as drug delivery and diagnosis agents in cancer treatment. The polymer colloids may be of different types such as micelles, liposomes, emulsions, cationic carriers, and hydrogels. The current article describes the state-of-the-art polymer colloids for the treatment of cancer. The contents of this article are about the role of polymeric nanomaterials with special emphasis on the different types of colloidal materials and their applications in targeted cancer therapy including cancer diagnoses. In addition, attempts are made to discuss future perspectives. This article will be useful for academics, researchers, and regulatory authorities.

Sustained Drug Release from Smart Nanoparticles in Cancer Therapy: A Comprehensive Review

Although nanomedicine has been highly investigated for cancer treatment over the past decades, only a few nanomedicines are currently approved and in the market; making this field poorly represented in clinical applications. Key research gaps that require optimization to successfully translate the use of nanomedicines have been identified, but not addressed; among these, the lack of control of the release pattern of therapeutics is the most important. To solve these issues with currently used nanomedicines (e.g., burst release, systemic release), different strategies for the design and manufacturing of nanomedicines allowing for better control over the therapeutic release, are currently being investigated. The inclusion of stimuli-responsive properties and prolonged drug release have been identified as effective approaches to include in nanomedicine, and are discussed in this paper. Recently, smart sustained release nanoparticles have been successfully designed to safely and efficiently deliver therapeutics with different kinetic profiles, making them promising for many drug delivery applications and in specific for cancer treatment. In this review, the state-of-the-art of smart sustained release nanoparticles is discussed, focusing on the design strategies and performances of polymeric nanotechnologies. A complete list of nanomedicines currently tested in clinical trials and approved nanomedicines for cancer treatment is presented, critically discussing advantages and limitations with respect to the newly developed nanotechnologies and manufacturing methods. By the presented discussion and the highlight of nanomedicine design criteria and current limitations, this review paper could be of high interest to identify key features for the design of release-controlled nanomedicine for cancer treatment.

Effect of Particle Carriers for Intraperitoneal Drug Delivery on the Course of Ovarian Cancer and Its Immune Microenvironment in a Mouse Model

Novel treatment strategies are needed to provide a better prognosis for ovarian cancer. For this purpose, the current study was designed to evaluate the effects of different types of particle drug carriers on tumor response and on the tumor immune microenvironment (TME) after intraperitoneal (IP) administration in a murine tumor model. Mice with ID8-fLuc ovarian cancer were injected IP with pegylated liposomes, hydroxyapatite, polystyrene, poly(lactic-co-glycolic acid) (PLGA) and calcium carbonate (CaCO₃) microparticles to evaluate the effect of the candidate carriers without drugs. Our results show that several types of microparticle drug carriers caused hyperproliferation of the tumor when injected IP, as reflected in a reduced survival or an accelerated onset of ascites. Alterations of the product formulation of CaCO₃ microparticles could result in less hyperproliferation. The hyperproliferation caused by CaCO₃ and PLGA was largely driven by a strong innate immune suppression. A combination with chemotherapy was not able to sufficiently counteract the tumor progression caused by the drug carriers. This research points towards the importance of evaluating a drug carrier before using it in a therapeutic setting, since drug carriers themselves can detrimentally influence tumor progression and immune status of the TME. However, it remains to be determined whether the hyperproliferation in this model will be of relevance in other cancer models or in humans.

Submicron particle docetaxel intratumoral injection in combination with anti-mCTLA-4 into 4T1-Luc orthotopic implants reduces primary tumor and metastatic pulmonary lesions

We describe here characterization of the response of local and metastatic disease and immunomodulation following intratumoral (IT) injection of submicron particle docetaxel (SPD) administered alone or in combination with systemic antibody anti-mCTLA-4 (anti-mCTLA-4) in the metastatic 4T1-Luc2-1A4 (4T1) murine breast cancer model. In-life assessments of treatment tolerance, tumor volume (TV), and metastasis were performed (n = 10 animals/group). At study end, immune cell populations in tumor-site tissues and peripheral blood were analyzed using flow cytometry. Signs of distress typical of this aggressive tumor model occurred across all animals except for the combination treated which were asymptomatic and gained weight. TV at study end was significantly reduced in the combination group versus untreated [43% reduced (p < 0.05)] and vehicle controls [54% reduced (p < 0.0001)]. No evidence of thoracic metastasis was found in 40% of combination group animals and thoracic bioluminescence imaging (BLI) was reduced vs. untreated controls (p < 0.01). Significant elevations (p < 0.05) in CD4 + T, CD4 + helper T, Treg, and NKT cells were found in tumor and blood in SPD or combination treatment compared to controls or anti-mCTLA-4. Combination treatment increased tumor-associated CD8 + T cells (p < 0.01), peripheral B cells (p < 0.01), and tumor associated and circulating dendritic cells (DC) (p < 0.05). Tumor-associated NK cells were significantly increased in SPD ± anti-mCTLA-4 treatments (p < 0.01). Myeloid-derived suppressor cells (MDSC) were reduced in bloods in SPD ± anti-mCTLA-4 groups (p < 0.05). These data demonstrate that both SPD and anti-mCTLA-4 produce local anti-tumor effects as well as reductions in metastasis which are significantly enhanced when administered in combination.

Pharmaceutical strategies in improving anti-tumour efficacy and safety of intraperitoneal therapy for peritoneal metastasis

Introduction: In selected patients with limited peritoneal metastasis (PM), favorable tumor biology, and a good clinical condition, there is an indication for combination of cytoreductive surgery (CRS) and subsequent intravenous (IV) or intraperitoneal (IP) chemotherapy. Compared with IV injection, IP therapy can achieve a high drug concentration within the peritoneal cavity with low systemic toxicity, however, the clinical application of IP chemotherapy is limited by the related abdominal pain, infection, and intolerance.Areas covered:To improve the anti-tumor efficacy and safety of IP therapy, various pharmaceutical strategies have been developed and show promising potential. This review discusses the specialized modification of traditional drug delivery systems and demonstrates the preparation of customized drug carriers for IP therapy, including chemotherapy and gene therapy. IP therapy has important clinical significance in the treatment of PM using novel anti-tumor agents as well as conventional drugs in new applications.Expert opinion: Although IP therapy exhibits good performance both in mouse models and in patients with PM in clinical trials, its clinical application remains limited due to the serious side effects and low acceptability. Further investigations, including pharmaceutical strategies, are needed to develop potential IP therapy, focusing on the efficacy and safety thereof.

Loco-regional drug delivery in oncology: current clinical applications and future translational opportunities

Introduction: Drug-based treatment regimens for cancer are often associated with off-target toxic side effects and low penetration of the drug at the tumor site leading to patient morbidity and limited efficacy. Loco-regional drug delivery has the potential to increase efficacy while concomitantly reducing toxicity.Areas covered: Clinical applications using loco-regional delivery include intra-arterial drug delivery in retinoblastoma, direct intra-tumoral (IT) injection of ethanol for ablation in hepatocellular carcinoma (HCC) and the use of HIPEC in peritoneal carcinomas. In recent years, there has been a significant increase in both approved products and clinical trials, with a particular emphasis on drug delivery platforms such as drug-eluting beads for HCC and hydrogel platforms for intravesical delivery in bladder cancer.Expert opinion: Development of loco-regional drug-delivery systems has been slow, limited by weak clinical data for early applications and challenges relating to dosing, delivery and retention of drugs at the site of action. However, there is increasing focus on the potential of loco-regional drug delivery when combined with bespoke drug-delivery platforms. With the growth in immunotherapies, the use of IT delivery to drive priming of the anti-tumor response has opened up a new field of opportunity for loco-regional drug delivery.

Local administration of submicron particle paclitaxel to solid carcinomas induces direct cytotoxicity and immune-mediated tumoricidal effects without local or systemic toxicity: preclinical and clinical studies

This report describes local administration of submicron particle paclitaxel (SPP) (NanoPac®: ~ 800-nm-sized particles with high relative surface area with each particle containing ~ 2 billion molecules of paclitaxel) in preclinical models and clinical trials evaluating treatment of carcinomas. Paclitaxel is active in the treatment of epithelial solid tumors including ovarian, peritoneal, pancreatic, breast, esophageal, prostate, and non-small cell lung cancer. SPP has been delivered directly to solid tumors, where the particles are retained and continuously release the drug, exposing primary tumors to high, therapeutic levels of paclitaxel for several weeks. As a result, tumor cell death shifts from primarily apoptosis to both apoptosis and necroptosis. Direct local tumoricidal effects of paclitaxel, as well as stimulation of innate and adaptive immune responses, contribute to antineoplastic effects. Local administration of SPP may facilitate tumor response to systemically administered chemotherapy, targeted therapy, or immunotherapy without contributing to systemic toxicity. Results of preclinical and clinical investigations described here suggest that local administration of SPP achieves clinical benefit with negligible toxicity and may complement standard treatments for metastatic disease.

Phase II study of intraperitoneal submicron particle paclitaxel (SPP) plus IV carboplatin and paclitaxel in patients with epithelial ovarian cancersurgery

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Patients with ovarian cancer were treated with intraperitoneal submicron particle paclitaxel after debulking surgery.

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Following surgery, patients received IV chemotherapy without evidence of enhanced systemic toxicity.

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By RECIST 1.1 criteria, 66% of patients had progression free survival at 6 months and 1-year following surgery.

Submicron particles (~800 nm) of paclitaxel (SPP) contain 1–2 billion molecules of pure drug that release tumoricidal levels of paclitaxel over many weeks. This study compared two dose-levels of SPP instilled into the peritoneal cavity (IP) in 200 ml of saline post-cytoreductive surgery. Eligible patients with primary (n = 6) or recurrent (n = 4) epithelial ovarian cancer who underwent complete cytoreductive surgery were enrolled to receive a single instillation of IP SPP followed by standard IV carboplatin and paclitaxel. Endpoints were PFS and evaluation of treatment emergent adverse events. Clinical response was determined by symptoms, physical exams, CT scans, and serum CA-125 measurements. Of the 24 subjects screened, 10 were enrolled and received treatment: seven patients received 100 mg/m² and three received 200 mg/m². Seven subjects completed the 12-month follow-up period. Six patients were evaluable due to one subject who had unevaluable scans throughout the follow-up period and was thus excluded from PFS determination. Upon completion of planned chemotherapy post-SPP instillation, the PFS at 6 months was 66% (4/6) and at 12-months 66% (4/6) using RECIST 1.1. One subject had a complete response at the end of IV treatment but died (unrelated to study treatment) before PFS evaluation. There was one case of incision dehiscence and one case of vaginal cuff leakage after surgery. This pilot study supports further evaluation of IP SPP to treat peritoneal carcinomas.

Intraperitoneal chemotherapy for peritoneal metastases: an expert opinion

Introduction: The rationale for intraperitoneal (IP) drug delivery for patients with peritoneal metastases (PM) is based on the pharmacokinetic advantage resulting from the peritoneal-plasma barrier, and on the potential to adequately treat small, poorly vascularized PM. Despite a history of more than three decades, many aspects of IP drug delivery remain poorly studied.Areas covered: We outline the anatomy and physiology of the peritoneal cavity, including the pharmacokinetics of IP drug delivery. We discuss transport mechanisms governing tissue penetration of IP chemotherapy, and how these are affected by the biomechanical properties of the tumor stroma. We provide an overview of the current clinical evidence on IP chemotherapy in ovarian, colorectal, and gastric cancer. We discuss the current limitations of IP drug delivery and propose several potential areas of progress.Expert opinion: The potential of IP drug delivery is hampered by off-label use of drugs developed for systemic therapy. The efficacy of IP chemotherapy for PM depends on cancer type, disease extent, and mode of drug delivery. Results from ongoing randomized trials will allow to better delineate the potential of IP chemotherapy. Promising approaches include IP aerosol therapy, prolonged delivery platforms such as gels or biomaterials, and the use of nanomedicine.

Progress in Polymeric Nano-Medicines for Theranostic Cancer Treatment

Cancer is a life-threatening disease killing millions of people globally. Among various medical treatments, nano-medicines are gaining importance continuously. Many nanocarriers have been developed for treatment, but polymerically-based ones are acquiring importance due to their targeting capabilities, biodegradability, biocompatibility, capacity for drug loading and long blood circulation time. The present article describes progress in polymeric nano-medicines for theranostic cancer treatment, which includes cancer diagnosis and treatment in a single dosage form. The article covers the applications of natural and synthetic polymers in cancer diagnosis and treatment. Efforts were also made to discuss the merits and demerits of such polymers; the status of approved nano-medicines; and future perspectives.

Peritoneal Metastases in Colorectal Cancer: Biology and Barriers

BACKGROUND

Advances in the molecular biology of tumor metastasis have paralleled the evolution in the management of metastatic disease from colorectal cancer. In this review, we summarize the current understanding of the mechanism of colorectal cancer metastases, in particular that of peritoneal metastases, as well as clinical data on the treatment of this disease.

METHODS

A review of relevant English literature using MEDLINE/PubMed on the biology of colorectal cancer metastases, determinants of oligometastasis, and use of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in the treatment of metastatic colorectal cancer is presented.

RESULTS

Recognition of oligometastasis in the evolution of colorectal peritoneal metastases provides the theoretical framework for which cytoreductive surgery with or without hyperthermic intraperitoneal chemotherapy is considered. Clearly, a subset of patients benefit from peritoneal metastasectomy.

CONCLUSION

Advances in cancer biology and clinical imaging promise to expand the role of cytoreductive surgery with or without intraperitoneal chemotherapy in the management of peritoneal metastases from colorectal cancer.

Inhaled Submicron Particle Paclitaxel (NanoPac) Induces Tumor Regression and Immune Cell Infiltration in an Orthotopic Athymic Nude Rat Model of Non-Small Cell Lung Cancer

Background: This study evaluated the antineoplastic and immunostimulatory effects of inhaled (IH) submicron particle paclitaxel (NanoPac^®) in an orthotopic non-small cell lung cancer rodent model.

Methods: Male nude rats were whole body irradiated, intratracheally instilled with Calu-3 cancer cells and divided into six treatment arms (n = 20 each): no treatment (Group 1); intravenous nab-paclitaxel at 5.0 mg/kg once weekly for 3 weeks (Group 2); IH NanoPac at 0.5 or 1.0 mg/kg, once weekly for 4 weeks (Groups 3 and 4), or twice weekly for 4 weeks (Groups 5 and 6). Upon necropsy, left lungs were paraffin embedded, serially sectioned, and stained for histopathological examination. A subset was evaluated by immunohistochemistry (IHC), anti-pan cytokeratin staining AE1/AE3⁺ tumor cells and CD11b⁺ staining dendritic cells, natural killer lymphocytes, and macrophage immune cells (n = 2, Group 1; n = 3 each for Groups 2–6). BCL-6 staining identified B lymphocytes (n = 1 in Groups 1, 2, and 6).

Results: All animals survived to scheduled necropsy, exhibited no adverse clinical observations due to treatment, and gained weight at the same rate throughout the study. Histopathological evaluation of Group 1 lung samples was consistent with unabated tumor growth. Group 2 exhibited regression in 10% of animals (n = 2/20). IH NanoPac-treated groups exhibited significantly higher tumor regression incidence per group (n = 11–13/20; p < 0.05, χ²). IHC subset analysis revealed tumor-nodule cluster separation, irregular borders between tumor and non-neoplastic tissue, and an increased density of infiltrating CD11b⁺ cells in Group 2 animals (n = 2/3) and in all IH NanoPac-treated animals reviewed (n = 3/3 per group). A single animal in Group 4 and Group 6 exhibited signs of pathological complete response at necropsy with organizing stroma and immune cells replacing areas presumed to have previously contained adenocarcinoma nodules.

Conclusion: Tumor regression and immune cell infiltration were observed in all treatment groups, with an increased incidence noted in animals receiving IH submicron particle paclitaxel treatment.

Enhanced anti-tumor efficacy and safety with metronomic intraperitoneal chemotherapy for metastatic ovarian cancer using biodegradable nanotextile implants

The objective of this study was to evaluate intraperitoneal (IP) metronomic chemotherapy using sustained release paclitaxel (PTX) delivery from electrospun biodegradable polymeric yarns woven into suturable nanotextiles. Following confirmation of in vitro PTX efficacy in ID8-VEGF epithelial ovarian cancer cells, in vivo studies were performed upon surgical peritoneal implantation of nanotextile implants in orthotopic, syngeneic ID8-VEGF tumor-bearing C57BL/6 mice. In comparison to the clinical PTX-solution, there was a significant enhancement of anti-tumor efficacy and safety with PTX-nanotextiles. After 35-days, the peritoneum of tumor-bearing mice with PTX-nanotextiles was completely devoid of tumor nodules and ascitic fluid. Additionally, VEGF levels measured in peritoneal lavage fluid were 300-fold lower compared to PTX-solution and 600-fold lower as compared to untreated tumor-bearing animals. PTX-solution treated group also developed severe metastatic lesions and progressive ascitic fluid buildup. More importantly, no signs of systemic/ organ toxicity were observed in PTX-nanotextile implanted mice, unlike the systemic toxic effects induced by PTX-solution. Collectively, our results show the therapeutic and safety advantages offered by combining clinically translatable metronomic low-dose chemotherapy and IP pharmacokinetics using biodegradable nanotextile implants in addressing the challenges of late-stage ovarian cancer.

Aerosolization of Nanotherapeutics as a Newly Emerging Treatment Regimen for Peritoneal Carcinomatosis

Recent advances in locoregional chemotherapy have opened the door to new approaches for the clinical management of peritoneal carcinomatosis (PC) by facilitating the delivery of anti-neoplastic agents directly to the tumor site, while mitigating adverse effects typically associated with systemic administration. In particular, an innovative intra-abdominal chemotherapeutic approach, known as Pressurized Intraperitoneal Aerosol Chemotherapy (PIPAC), was recently introduced to the intraperitoneal (IP) therapy regimens as a palliative therapeutic option in patients with PC, presumably providing a better drug distribution pattern together with deeper drug penetration into tumor nodules within the peritoneal space. Furthermore, the progress of nanotechnology in the past few decades has prompted the application of different nanomaterials in IP cancer therapy, offering new possibilities in this field ranging from an extended retention time to sustained drug release in the peritoneal cavity. This review highlights the progress, challenges, and opportunities in utilizing cancer nanotherapeutics for locoregional drug delivery, with a special emphasis on the aerosolization approach for intraperitoneal therapies.

Local Injection of Submicron Particle Docetaxel is Associated with Tumor Eradication, Reduced Systemic Toxicity and an Immunologic Response in Uro-Oncologic Xenografts

Intratumoral (IT) administration of submicron particle docetaxel (NanoDoce^®, NanOlogy LLC, Fort Worth, TX, USA) and its efficacy against genitourinary-oncologic xenografts in rats and mice, xenograft-site docetaxel concentrations and immune-cell infiltration were studied. IT-NanoDoce^®, IV-docetaxel and IT-vehicle were administered to clear cell renal carcinoma (786-O: rats), transitional cell bladder carcinoma (UM-UC-3: mice) and prostate carcinoma (PC-3: mice). Treatments were given every 7 days with 1, 2, or 3 doses administered. Animals were followed for tumor growth and clinical signs. At necropsy, 786-O and UM-UC-3 tumor-site tissues were evaluated by H&E and IHC and analyzed by LC-MS/MS for docetaxel concentration. Two and 3 cycles of IT-NanoDoce^® significantly reduced UM-UC-3 tumor volume (p < 0.01) and eliminated most UM-UC-3 and 786-O tumors. In both models, NanoDoce^® treatment was associated with (peri)tumor-infiltrating immune cells. Lymphoid structures were observed in IT-NanoDoce^®-treated UM-UC-3 animals adjacent to tumor sites. IT-vehicle and IV-docetaxel exhibited limited immune-cell infiltration. In both studies, high levels of docetaxel were detected in NanoDoce^®-treated animals up to 50 days post-treatment. In the PC-3 study, IT-NanoDoce^® and IV-docetaxel resulted in similar tumor reduction. NanoDoce^® significantly reduced tumor volume compared to IT-vehicle in all xenografts (p < 0.0001). We hypothesize that local, persistent, therapeutic levels of docetaxel from IT-NanoDoce^® reduces tumor burden while increasing immune-cell infiltration. IT NanoDoce^® treatment of prostate, renal and bladder cancer may result in enhanced tumoricidal effects.

Evaluation of the Biological Behavior of a Gold Nanocore-Encapsulated Human Serum Albumin Nanoparticle (Au@HSANP) in a CT-26 Tumor/Ascites Mouse Model after Intravenous/Intraperitoneal Administration

Colorectal cancer is one of the major causes of cancer-related death in Taiwan and worldwide. Patients with peritoneal metastasis from colorectal cancer have reduced overall survival and poor prognosis. Hybrid protein-inorganic nanoparticle systems have displayed multifunctional applications in solid cancer theranostics. In this study, a gold nanocore-encapsulated human serum albumin nanoparticle (Au@HSANP), which is a hybrid protein-inorganic nanoparticle, and its radioactive surrogate ¹¹¹In-labeled Au@HSANP (¹¹¹In-Au@HSANP), were developed and their biological behaviors were investigated in a tumor/ascites mouse model. ¹¹¹In-Au@HSANP was injected either intravenously (iv) or intraperitoneally (ip) in CT-26 tumor/ascites-bearing mice. After ip injection, a remarkable and sustained radioactivity retention in the abdomen was noticed, based on microSPECT images. After iv injection, however, most of the radioactivity was accumulated in the mononuclear phagocyte system. The results of biodistribution indicated that ip administration was significantly more effective in increasing intraperitoneal concentration and tumor accumulation than iv administration. The ratios of area under the curve (AUC) of the ascites and tumors in the ip-injected group to those in the iv-injected group was 93 and 20, respectively. This study demonstrated that the ip injection route would be a better approach than iv injections for applying gold-albumin nanoparticle in peritoneal metastasis treatment.

Pharmacokinetic Profile of Inhaled Submicron Particle Paclitaxel (NanoPac®) in a Rodent Model

Background: Inhaled chemotherapeutics may enhance pulmonary drug exposure to malignant lesions in the lung without substantially contributing to systemic toxicities. The pharmacokinetic profile of inhaled submicron particle paclitaxel (NanoPac^®) in healthy rodent plasma and lung tissue is evaluated here to determine administration proof-of-principle.

Methods: Healthy male Sprague Dawley rats received paclitaxel in one of three arms: intravenous nab-paclitaxel at 2.9 mg/kg (IVnP), inhaled NanoPac low dose (IHNP-LD) at 0.38 mg/kg, or inhaled NanoPac high dose (IHNP-HD) at 1.18 mg/kg. Plasma and lung tissue paclitaxel concentrations were determined using ultraperformance liquid chromatography tandem mass spectrometry from animals sacrificed at 10 time points ranging up to 2 weeks after administration. Peak concentration (C_max), apparent residence half-life (T_1/2), exposure (AUC_(last)), and dose-normalized exposure (AUC_D(last)) were determined. Pulmonary histopathology was performed on rats sacrificed at the 336-hour time point.

Results: Paclitaxel was detectable and quantifiable in the rat lung for both inhaled NanoPac arms sampled at the final necropsy, 336 hours postadministration. Substantial paclitaxel deposition and retention resulted in an order of magnitude increase in dose-normalized pulmonary exposure over IVnP. Inhaled NanoPac arms had an order of magnitude lower plasma C_max than IVnP, but followed a similar plasma T_1/2 clearance (quantifiable only to 72 hours postadministration). Pulmonary histopathology found all treated animals indistinguishable from treatment-naive rats.

Conclusion: In the rodent model, inhaled NanoPac demonstrated substantial deposition and retention of paclitaxel in sampled lung tissue. Further research to determine NanoPac's toxicity profile and potential efficacy as lung cancer therapy is underway.

Long-term drug delivery using implantable electrospun woven polymeric nanotextiles

A woven nanotextile implant was developed and optimized for long-term continuous drug delivery for potential oncological applications. Electrospun polydioxanone (PDS) nanoyarns, which are twisted bundles of PDS nanofibres, were loaded with paclitaxel (PTX) and woven into nanotextiles of different packing densities. A mechanistic modeling of in vitro drug release proved that a combination of diffusion and matrix degradation controlled the slow PTX-release from a nanoyarn, emphasizing the role of nanostructure in modulating release kinetics. Woven nanotextiles, through variations in its packing density and thereby architecture, demonstrated tuneable PTX-release. In vivo PTX-release, pharmacokinetics and biodistribution were evaluated in healthy BALB/c mice by suturing the nanotextile to peritoneal wall. The slow and metronomic PTX-release for 60 days from the loosely woven implant was extremely effective in enhancing its residence in peritoneum, in contrast to intraperitoneal injections. Such an implantable matrix offers a novel platform for therapy of solid tumors over prolonged durations.

Magnetically assisted intraperitoneal drug delivery for cancer chemotherapy

Intraperitoneal (IP) chemotherapy has revived hopes during the past few years for the management of peritoneal disseminations of digestive and gynecological cancers. Nevertheless, a poor drug penetration is one key drawback of IP chemotherapy since peritoneal neoplasms are notoriously resistant to drug penetration. Recent preclinical studies have focused on targeting the aberrant tumor microenvironment to improve intratumoral drug transport. However, tumor stroma targeting therapies have limited therapeutic windows and show variable outcomes across different cohort of patients. Therefore, the development of new strategies for improving the efficacy of IP chemotherapy is a certain need. In this work, we propose a new magnetically assisted strategy to elevate drug penetration into peritoneal tumor nodules and improve IP chemotherapy. A computational model was developed to assess the feasibility and predictability of the proposed active drug delivery method. The key tumor pathophysiology, including a spatially heterogeneous construct of leaky vasculature, nonfunctional lymphatics, and dense extracellular matrix (ECM), was reconstructed in silico. The transport of intraperitoneally injected magnetic nanoparticles (MNPs) inside tumors was simulated and compared with the transport of free cytotoxic agents. Our results on magnetically assisted delivery showed an order of magnitude increase in the final intratumoral concentration of drug-coated MNPs with respect to free cytotoxic agents. The intermediate MNPs with the radius range of 200-300 nm yield optimal magnetic drug targeting (MDT) performance in 5-10 mm tumors while the MDT performance remains essentially the same over a large particle radius range of 100-500 nm for a 1 mm radius small tumor. The success of MDT in larger tumors (5-10 mm in radius) was found to be markedly dependent on the choice of magnet strength and tumor-magnet distance while these two parameters were less of a concern in small tumors. We also validated in silico results against experimental results related to tumor interstitial hypertension, conventional IP chemoperfusion, and magnetically actuated movement of MNPs in excised tissue.

Evaluating the Accelerated Blood Clearance Phenomenon of PEGylated Nanoemulsions in Rats by Intraperitoneal Administration

The accelerated blood clearance (ABC) phenomenon is induced by repeated intravenous injection of stealth polyethylene glycol (PEG) nanocarriers and appears as the alteration of the pharmacokinetics and biodistribution of the second administration. Nevertheless, there is no any report about the ABC phenomenon induced by intraperitoneal administration of PEGylated nanocarriers. In this study, we firstly observed whether the ABC phenomenon is induced with PEGylated nanoemulsion at the dose of 0.5~100 μmol phospholipid·kg^-1 by intraperitoneal/intravenous injections in rats. The PEG (molecule weight, 2000)-modified nanoemulsions PE-B and PE in which fluorescence indicator dialkylcarbocyanines (DiR) is encapsulated by PE-B were prepared for this work. The pharmacokinetics of the first injected PE via veins or peritoneal cavity features different variation trends. Moreover, the tissue distributions (in vivo or in vitro) of the first injected PE by intraperitoneal injection reveals that the PE gains access to the whole lymphatic circulatory system. Furthermore, our results demonstrate that the ABC phenomenon can be induced by intraperitoneal administration PE-B and present obvious changes with varying PE-B concentration 0.5~100 μmol phospholipid·kg^-1. Moreover, an interesting point is that the ABC phenomenon induced by intraperitoneal injected PE-B can be significantly inhibited by intraperitoneal pre-injection of distilled water. For understanding this issue clear, we studied the production of anti-PEG IgM and the characteristic morphologies of immune cells. We observed that the mast cells in peritoneal cavity exhibit rapid depletion in response to the intraperitoneal pre-injection of distilled water, while the anti-PEG IgM secretes at the same level.

Imaging and therapy of ovarian cancer: clinical application of nanoparticles and future perspectives

Despite significant advances in cancer diagnostics and treatment, ovarian cancers (OC) continue to kill more than 150,000 women every year worldwide. Due to the relatively asymptomatic nature and the advanced stage of the disease at the time of diagnosis, OC is the most lethal gynecologic malignancy. The current treatment for advanced OC relies on the synergistic effect of combining surgical cytoreduction and chemotherapy; however, beside the fact that chemotherapy resistance is a major challenge in OC management, new imaging strategies are needed to target microscopic lesions and improve both cytoreductive surgery and patient outcomes. In this context, nanostructured probes are emerging as a new class of medical tool that can simultaneously provide imaging contrast, target tumor cells, and carry a wide range of medicines resulting in better diagnosis and therapeutic precision. Herein we summarize several exemplary efforts in nanomedicine for addressing unmet clinical needs.

Drug Delivery in Cancer Therapy, Quo Vadis?

The treatment of malignancies has undergone dramatic changes in the past few decades. Advances in drug delivery techniques and nanotechnology have allowed for new formulations of old drugs, so as to improve the pharmacokinetics, to enhance accumulation in solid tumors, and to reduce the significant toxic effects of these important therapeutic agents. Here, we review the published clinical data in cancer therapy of several major drug delivery systems, including targeted radionuclide therapy, antibody-drug conjugates, liposomes, polymer-drug conjugates, polymer implants, micelles, and nanoparticles. The clinical outcomes of these delivery systems from various phases of clinical trials are summarized. The success and limitations of the drug delivery strategies are discussed based on the clinical observations. In addition, the challenges in applying drug delivery for efficacious cancer therapy, including physical barriers, tumor heterogeneity, drug resistance, and metastasis, are discussed along with future perspectives of drug delivery in cancer therapy. In doing so, we intend to underscore that efficient delivery of cancer therapeutics to solid malignancies remains a major challenge in cancer therapy, and requires a multidisciplinary approach that integrates knowledge from the diverse fields of chemistry, biology, engineering, and medicine. The overall objective of this review is to improve our understanding of the clinical fate of commonly investigated drug delivery strategies, and to identify the limitations that must be addressed in future drug delivery strategies, toward the pursuit of curative therapies for cancer.

Intraperitoneal chemotherapy for ovarian cancer using sustained-release implantable devices

INTRODUCTION

Epithelial ovarian cancer (EOC) remains to be the most lethal of all gynecological malignancies mainly due to its asymptomatic nature. The late stages are manifested with predominant metastases confined to the peritoneal cavity. Although there has been a substantial progress in the treatment avenue with different therapeutic interventions, the overall survival rate of patients remain poor due to relapse and drug resistance.

AREAS COVERED

The pharmacokinetic advantages offered by intraperitoneal (IP) chemotherapy due to peritoneal-plasma barrier can be potentially exploited for EOC relapse treatment. The ability to retain high concentrations of chemo-drugs with high AUC peritoneum/plasma for prolonged durations in the peritoneal cavity can be utilized effectively through the clinical adoption of drug delivery systems (DDSs) which obviates the need for indwelling catheters. The metronomic dosing strategy could enhance anti-tumor efficacy with a continuous, low dose of chemo-drugs providing minimal systemic toxicity.

EXPERT OPINION

The development of a feasible, non-catheter based, IP DDS, retaining the peritoneal-drug levels, with less systemic levels could offer significant survival advantages as a patient-compliant therapeutic strategy. Suturable-implantable devices based on metronomic dosing, eluting drug in a sustained manner at low doses, could be implanted surgically post-debulking for treatment of refractory EOC patients.

Nanoparticle as a novel tool in hyperthermic intraperitoneal and pressurized intraperitoneal aerosol chemotheprapy to treat patients with peritoneal carcinomatosis

The treatment of peritoneal surface malignances has changed considerably over the last thirty years. Unfortunately, the palliative is the only current treatment for peritoneal carcinomatosis (PC). Two primary intraperitoneal chemotherapeutic methods are used. The first is combination of cytoreductive surgery (CRS) and Hyperthermic IntraPEritoneal Chemotherapy (HIPEC), which has become the gold standard for many cases of PC. The second is Pressurized IntraPeritoneal Aerosol Chemotheprapy (PIPAC), which is promising direction to minimally invasive as safedrug delivery. These methods were improved through multicenter studies and clinical trials that yield important insights and solutions. Major method development has been made through nanomedicine, specifically nanoparticles. Here, we are presenting the latest advances of nanoparticles and their application to precision diagnostics and improved treatment strategies for PC. These advances will likely develop both HIPEC and PIPAC methods that used for in vitro and in vivo studies. Several benefits of using nanoparticles will be discussed including: 1) Nanoparticles as drug delivery systems; 2) Nanoparticles and Near Infrred (NIR) Irradiation; 3) use of nanoparticles in perioperative diagnostic and individualized treatment planning; 4) use of nanoparticles as anticancer dressing's, hydrogels and as active beeds for optimal reccurence prevention; and 5) finally the curent in vitro and in vivo studies and clinical trials of nanoparticles. The current review highlighted use of nanoparticles as novel tools in improving drug delivery to be effective for treatment patients with peritoneal carcinomatosis.

Pharmacokinetic studies and anticancer activity of curcumin-loaded nanostructured lipid carriers

In order to investigate the potential of nanostructured lipid carriers for efficient and targeted delivery of curcumin, the pharmacokinetic parameters of curcumin-loaded nanostructured lipid carriers (Cur-NLC) were evaluated in rats after a single intraperitoneal dose of Cur-NLC. In addition, the anticancer activity of Cur-NLC against human lung adenocarcinoma A549 cells was verified by a cellular uptake study, and a cytotoxicity and apoptosis assay. Bioavailability of Cur-NLC was better than that of native curcumin (p > 0.01), as seen from the area under the plasma concentration-time curve (AUC), maximum plasma concentration (Cmax), mean residence time (MRT) and total plasma clearance (CLz/F). Cur-NLC has a more obvious lung-targeting property in comparison with native curcumin. Cur-NLC showed higher anticancer activity in vitro against A549 cells than native curcumin (IC50 value of 5.66 vs. 9.81 mg L-1, respectively). Meanwhile, Cur-NLC treated A549 cells showed a higher apoptosis rate compared to that of native curcumin. These results indicate that NLC is a promising system for the delivery of curcumin in the treatment of lung adenocarcinoma.

Targeting of p32 in peritoneal carcinomatosis with intraperitoneal linTT1 peptide-guided pro-apoptotic nanoparticles

Gastrointestinal and gynecological malignancies disseminate in the peritoneal cavity - a condition known as peritoneal carcinomatosis (PC). Intraperitoneal (IP) administration can be used to improve therapeutic index of anticancer drugs used for PC treatment. Activity of IP anticancer drugs can be further potentiated by encapsulation in nanocarriers and/or affinity targeting with tumor-specific affinity ligands, such as tumor homing peptides. Here we evaluated a novel tumor penetrating peptide, linTT1 (AKRGARSTA), as a PC targeting ligand for nanoparticles. We first demonstrated that the primary homing receptor for linTT1, p32 (or gC1qR), is expressed on the cell surface of peritoneal carcinoma cell lines of gastric (MKN-45P), ovarian (SKOV-3), and colon (CT-26) origin, and that peritoneal tumors in mice and clinical peritoneal carcinoma explants express p32 protein accessible from the IP space. Iron oxide nanoworms (NWs) functionalized with the linTT1 peptide were taken up and routed to mitochondria in cultured PC cells. NWs functionalized with linTT1 peptide in tandem with a pro-apoptotic [D(KLAKLAK)2] peptide showed p32-dependent cytotoxicity in MKN-45P, SKOV-3, and CT-26 cells. Upon IP administration in mice bearing MKN-45P, SKOV-3, and CT-26 tumors, linTT1-functionalized NWs showed robust homing and penetration into malignant lesions, whereas only a background accumulation was seen in control tissues. In tumors, the linTT1-NW accumulation was seen predominantly in CD31-positive blood vessels, in LYVE-1-positive lymphatic structures, and in CD11b-positive tumor macrophages. Experimental therapy of mice bearing peritoneal MKN-45P xenografts and CT-26 syngeneic tumors with IP linTT1-D(KLAKLAK)2-NWs resulted in significant reduction of weight of peritoneal tumors and significant decrease in the number of metastatic tumor nodules, whereas treatment with untargeted D(KLAKLAK)2-NWs had no effect. Our data show that targeting of p32 with linTT1 tumor-penetrating peptide improves tumor selectivity and antitumor efficacy of IP pro-apoptotic NWs. P32-directed intraperitoneal targeting of other anticancer agents and nanoparticles using peptides and other affinity ligands may represent a general strategy to increase their therapeutic index.

Cancer drug delivery in the nano era: An overview and perspectives (Review)

Nanomaterials are increasingly used as drug carriers for cancer therapy. Nanomaterials also appeal to researchers in the areas of cancer diagnosis and biomarker discovery. Several antitumor nanodrugs are currently being tested in preclinical and clinical trials and show promise in therapeutic and other settings. We review the development of nanomaterial drug carriers, including liposomes, polymer nanoparticles, dendritic polymers, and nanomicelles, for the diagnosis and treatment of various cancers. The prospects of nanomaterials as drug carriers for future clinical applications are also discussed.

Nanomedicine-based intraperitoneal therapy for the treatment of peritoneal carcinomatosis - Mission possible?

Intraperitoneal (IP) drug delivery represents an attractive strategy for the local treatment of peritoneal carcinomatosis (PC). Over the past decade, a lot of effort has been put both in the academia and clinic in developing IP therapeutic approaches that maximize local efficacy while limiting systemic side effects. Also nanomedicines are under investigation for the treatment of tumors confined to the peritoneal cavity, due to their potential to increase the peritoneal retention and to target drugs to the tumor sites as compared to free drugs. Despite the progress reported by multiple clinical studies, there are no FDA approved drugs or formulations for specific use in the IP cavity yet. This review discusses the current clinical management of PC, as well as recent advances in nanomedicine-based IP delivery. We address important challenges to be overcome towards designing optimal nanocarriers for IP therapy in vivo.

Pharmacokinetic problems in peritoneal drug administration: an update after 20 years

Intraperitoneal chemotherapy has demonstrated significant pharmacologic and clinical advantage over traditional intravenous administration for cancers that are restricted to the peritoneal cavity. The combination of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) has become the standard technique used to fight ovarian and gastrointestinal cancers in many centers. However, challenges remain for HIPEC to contact the entire peritoneal surface, penetrate the tumor tissue, and transport to the lymphatics and other metastatic sites. New innovations in delivery technique, such as heated aerosol, and in delivery molecules, such as microparticles, nanoparticles, nanogels, and tumor-penetrating peptides are being tested in animal models and will likely soon be in human trials. Improvements in overall care, such as the recent clinical trial of an oral agent for maintenance therapy in ovarian carcinoma, will continue in this field for the next 20 years.