Novel strategic therapeutic approaches for prevention of local recurrence of pancreatic cancer after resection: trans-tissue, sustained local drug-delivery systems

An in situ forming gel co-loaded with pirarubicin and celecoxib inhibits postoperative recurrence and metastasis of breast cancer

Surgical removal combined with postoperative chemotherapy is still the mainstay of treatment for most solid tumors. Although chemotherapy reduces the risk of recurrence and metastasis after surgery, it may produce serious adverse effects and impair patient compliance. In situ drug delivery systems are promising tools for postoperative cancer treatment, improving drug delivery efficiency and reducing side effects. Herein, an injectable phospholipid-based in situ forming gel (IPG) was prepared for the co-delivery of antitumor agent pirarubicin (THP) and cyclooxygenase-2 (COX-2) inhibitor celecoxib (CXB) in the surgical incision, and the latter are used extensively in adjuvant chemotherapy for cancer. After injection, the IPG co-loaded with THP and CXB (THP-CXB-IPG) underwent spontaneous phase transition and formed a drug reservoir that fitted the irregular surgical incisions perfectly. In vitro drug release studies and in vivo pharmacokinetic analysis had demonstrated the sustained release behaviors of THP-CXB-IPG. The in vivo therapeutic efficacy was evaluated in mice that had undergone surgical resection of breast cancer, and the THP-CXB-IPG showed considerable inhibition of residual tumor growth after surgery and reduced the incidence of pulmonary metastasis. Moreover, it reduced the systemic toxicity of chemotherapeutic agents. Therefore, THP-CXB-IPG can be a promising candidate for preventing postoperative recurrence and metastasis.

An ameliorated anti-hTNF-α therapy for arthritis via carrier-free macromolecular nanoparticles consisted of infliximab

Infliximab (INF) is intravenously used for the clinical treatment of rheumatoid arthritis. However, it can cause serious side effects, which are mainly associated with systemic exposure and high doses. Here, we developed a modified hydrophobic ion-pairing complexes (INF HIPC) through the sequential introduction of bovine lactoferrin (BLF) and hyaluronic acid (HA) with opposite charges into the INF solution. INF and BLF were found to be not only integrally responsible for the structural integrity of HIPC but also were determined to have respective biological activities by binding human tumor necrosis factor-alpha (hTNF-α) or promoting the proliferation of osteoblasts. The INF HIPC had good stability, high drug-loading efficiency, and long-term retention effects. Whether via knee joint injection or intravenous injection, INF HIPC resulted in lower hTNF-α levels and less cartilage destruction than INFs in the transgenic mouse model. At the same time, INF HIPC could reduce toxicity based on body weight changes in transgenic mice. Our findings provide a simple and promising avenue to develop advanced delivery systems for other antibodies and macromolecules.

Pancreatic Cancer: Challenges and Opportunities in Locoregional Therapies

Simple Summary

Pancreatic cancer is a serious ongoing global health burden, with an overall 5-year survival rate of less than 5%. One major hurdle in the treatment of this disease is the predominantly elderly patient population, leading to their ineligibility for curative surgery and a low rate of successful outcomes. Systemic administration introduces chemo-agents throughout the body via the blood, attacking not only tumours but also healthy organs. When localised interventions are employed, chemo-agents are retained specifically at tumour site, minimizing unwanted toxicity. As a result, there is a growing interest in finding novel localised interventions as alternatives to systemic therapy. Here, we present a detailed review of current locoregional therapies used in pancreatic cancer therapy. This work aims to present a thorough guide for researchers and clinicians intended to employ established and novel localised interventions in the treatment of pancreatic cancer. Furthermore, we present our insights and opinions on the potential ideals to improve these tools.

Abstract

Pancreatic cancer (PC) remains the seventh leading cause of cancer-related deaths worldwide and the third in the United States, making it one of the most lethal solid malignancies. Unfortunately, the symptoms of this disease are not very apparent despite an increasing incidence rate. Therefore, at the time of diagnosis, 45% of patients have already developed metastatic tumours. Due to the aggressive nature of the pancreatic tumours, local interventions are required in addition to first-line treatments. Locoregional interventions affect a specific area of the pancreas to minimize local tumour recurrence and reduce the side effects on surrounding healthy tissues. However, compared to the number of new studies on systemic therapy, very little research has been conducted on localised interventions for PC. To address this unbalanced focus and to shed light on the tremendous potentials of locoregional therapies, this work will provide a detailed discussion of various localised treatment strategies. Most importantly, to the best of our knowledge, the aspect of localised drug delivery systems used in PC was unprecedentedly discussed in this work. This review is meant for researchers and clinicians considering utilizing local therapy for the effective treatment of PC, providing a thorough guide on recent advancements in research and clinical trials toward locoregional interventions, together with the authors’ insight into their potential improvements.

An anti-bacterial and anti-cancer fibrous membrane with multiple therapeutic effects for prevention of pancreatic cancer recurrence

Adjuvant systemic chemotherapy with gemcitabine (GEM) is recognized as the standard of care to improve the prognosis of patients with resected pancreatic cancer (PC); however, it is greatly limited by poor absorption of chemotherapy agents. Moreover, surgical site infection and Gammaproteobacteria-induced GEM resistance further decrease the chemotherapy efficacy and increase the risk of recurrence and even mortality. Here, we develop an implantable anti-bacterial and anti-cancer fibrous membrane (AAFM) to inhibit PC recurrence in a well-coordinated manner. Our AAFM can be readily prepared via simple co-electrospinning of GEM and poly-L-lactic acid (PLLA) and subsequent tannic acid (TA)-mediated in-situ generation of silver nanoparticles (AgNPs). The resultant membrane presents highly porous fibrous morphology and appropriate mechanical performance. Most importantly, we find the surface-deposited TA/AgNP complexes can exert multiple therapeutic effects: (1) they can act as a fence to extend GEM diffusion route, achieving a sustained drug release; (2) they can fight the pathogenic microorganisms in the local microenvironment and prevent infectious complications and alleviate Gammaproteobacteria-induced chemotherapy resistance; (3) they can combat residual cancer cells to synchronously strengthen the effectiveness of GEM-based chemotherapy. Altogether, our AAFM provides a proof-of-concept demonstration of the integrated anti-cancer and anti-bacterial strategy for enhanced therapeutic efficacy and will inspire the design of other high-performance implants for prevention of tumor relapse.

Replenishable drug depot to combat post-resection cancer recurrence

Local drug presentation made possible by drug-eluting depots has demonstrated benefits in a vast array of diseases, including in cancer, microbial infection and in wound healing. However, locally-eluting depots are single-use systems that cannot be refilled or reused after implantation at inaccessible sites, limiting their clinical utility. New strategies to noninvasively refill drug-eluting depots could dramatically enhance their clinical use. In this report we present a refillable hydrogel depot system based on bioorthogonal click chemistry. The click-modified hydrogel depots capture prodrug refills from the blood and subsequently release active drugs locally in a sustained manner. Capture of the systemically-administered refills serves as an efficient and non-toxic method to repeatedly refill depots. Refillable depots in combination with prodrug refills achieve sustained release at precancerous tumor sites to improve cancer therapy while eliminating systemic side effects. The ability to target tissues without enhanced permeability could allow the use of refillable depots in cancer and many other medical applications.

Cell-based drug-delivery platforms

Cell systems have recently emerged as biological drug carriers, as an interesting alternative to other systems such as micro- and nano-particles. Different cells, such as carrier erythrocytes, bacterial ghosts and genetically engineered stem and dendritic cells have been used. They provide sustained release and specific delivery of drugs, enzymatic systems and genetic material to certain organs and tissues. Cell systems have potential applications for the treatment of cancer, HIV, intracellular infections, cardiovascular diseases, Parkinson’s disease or in gene therapy. Carrier erythrocytes containing enzymes such us L-asparaginase, or drugs such as corticosteroids have been successfully used in humans. Bacterial ghosts have been widely used in the field of vaccines and also with drugs such as doxorubicin. Genetically engineered stem cells have been tested for cancer treatment and dendritic cells for immunotherapeutic vaccines. Although further research and more clinical trials are necessary, cell-based platforms are a promising strategy for drug delivery.

Lyophilized silk fibroin hydrogels for the sustained local delivery of therapeutic monoclonal antibodies

The development of sustained delivery systems compatible with protein therapeutics continues to be a significant unmet need. A lyophilized silk fibroin hydrogel matrix (lyogel) for the sustained release of pharmaceutically relevant monoclonal antibodies is described. Sonication of silk fibroin prior to antibody incorporation avoids exposing the antibody to the sol-gel transition inducing shear stress. Fourier Transform Infrared (FTIR) analysis showed no change in silk structural composition between hydrogel and lyogel or with increasing silk fibroin concentration. Antibody release from hydrogels occurred rapidly over 10 days regardless of silk concentration. Upon lyophilization, sustained antibody release was observed over 38 days from lyogels containing 6.2% (w/w) silk fibroin and above. In 3.2% (w/w) silk lyogels, antibody release was comparable to hydrogels. Swelling properties of lyogels followed a similar threshold behavior. Lyogels at 3.2% (w/w) silk recovered approximately 90% of their fluid mass upon rehydration, while approximately 50% fluid recovery was observed at 6.2% (w/w) silk and above. Antibody release was primarily governed by hydrophobic/hydrophilic silk-antibody interactions and secondarily altered by the hydration resistance of the lyogel. Hydration resistance was controlled by altering β-sheet (crystalline) density of the matrix. The antibody released from lyogels maintained biological activity. Silk lyogels offer an advantage as a delivery matrix over other hydrogel materials for the slow release of the loaded protein, making lyogels suitable for long-term sustained release applications.