Targeting cancer-associated fibroblasts by dual-responsive lipid-albumin nanoparticles to enhance drug perfusion for pancreatic tumor therapy

TPGS and chondroitin sulfate dual-modified lipid-albumin nanosystem for targeted delivery of chemotherapeutic agent against multidrug-resistant cancer

Multidrug resistance (MDR) remains the primary issue leading to the failure of chemotherapy. In this study, a d-α-tocopherol polyethylene 1000 glycol succinate (TPGS) and chondroitin sulfate (CS) dual-modified lipid-albumin nanosystem was constructed for targeted delivery of paclitaxel (PTX) in treating MDR cancer. The obtained nanosystem (TLA/PTX@CS) had an average size of around 176 nm and a negative zeta potential of around -18 mV. TPGS was confirmed to improve the intracellular accumulation of PTX and facilitate the mitochondrial-targeting of lipid-albumin nanosystem. Functionalized with the outer CS shell, TLA/PTX@CS entered MDR breast cancer (MCF-7/MDR) cells via CD44 receptor-mediated endocytosis. CS shell was degraded by concentrated hyaluronidase in the lysosomes, thereby releasing PTX into cytoplasm and inhibiting cell proliferation. In vivo studies revealed that TLA/PTX@CS possessed prolonged blood circulation, resulting in elevated tumor accumulation, excellent antitumor efficacy with a tumor inhibition ratio of 75.3%, and significant survival benefit in MCF-7/MDR tumor-bearing mice. Hence, this TPGS and CS dual-modified lipid-albumin nanosystem provides a promising strategy for targeted delivery of chemotherapeutic drug and reversal of MDR in cancer treatment.

Emerging strategies against tumor-associated fibroblast for improved the penetration of nanoparticle into desmoplastic tumor

The therapeutic effect of nanoparticles is limited in solid tumors, especially desmoplastic tumors, because the tumor matrix hinders the delivery of nanoparticles. As the most abundant cells in the tumor stroma, tumor-associated fibroblasts (TAFs) produce a dense extracellular matrix, which leads to higher tissue fluid pressure, thereby creating a physical barrier for nanoparticle delivery. Therefore, researchers focused on eliminating TAFs to combat desmoplastic tumors. In recent years, a series of methods for TAFs have been developed. In this paper, we first introduced the biological mechanism of TAFs hindering the penetration of nanoparticles. Then, the different methods of eliminating TAFs were summarized, and the mechanism of nanomedicine in eliminating TAFs was highlighted. Finally, the problems and future development directions for TAFs treatment were discussed from the perspective of the treatment of desmoplastic tumors.

Cell-specific drug targeting in the lung

Non-targeted drug delivery systems have several limitations including the decreased bioavailability of the drug, poor stability and rapid clearance in addition to off-target distribution. Cell-specific targeted delivery approaches promise to overcome some of these limitations and enhance therapeutic selectivity. In this review, we aim to discuss cell-specific targeted approachesin the lung at the biochemical and molecular levels. These approaches include;a) directly administered small molecule drugs with intracellular action; b) targeted biologics and synthetic hybrids with extracellular action; c) site activateddrugs; and d) delivery systems.We discuss the pharmaceutical and biochemical parameters that govern the fate of drug molecules at delivery sites while presenting an overview of relevant literature surrounding this area of research and current advancements.

Tailor-Made Nanomaterials for Diagnosis and Therapy of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers worldwide due to its aggressiveness and the challenge to early diagnosis and treatment. In recent decades, nanomaterials have received increasing attention for diagnosis and therapy of PDAC. However, these designs are mainly focused on the macroscopic tumor therapeutic effect, while the crucial nano-bio interactions in the heterogeneous microenvironment of PDAC remain poorly understood. As a result, the majority of potent nanomedicines show limited performance in ameliorating PDAC in clinical translation. Therefore, exploiting the unique nature of the PDAC by detecting potential biomarkers together with a deep understanding of nano-bio interactions that occur in the tumor microenvironment is pivotal to the design of PDAC-tailored effective nanomedicine. This review will introduce tailor-made nanomaterials-enabled laboratory tests and advanced noninvasive imaging technologies for early and accurate diagnosis of PDAC. Moreover, the fabrication of a myriad of tailor-made nanomaterials for various PDAC therapeutic modalities will be reviewed. Furthermore, much preferred theranostic multifunctional nanomaterials for imaging-guided therapies of PDAC will be elaborated. Lastly, the prospects of these nanomaterials in terms of clinical translation and potential breakthroughs will be briefly discussed.

When Albumin Meets Liposomes: A Feasible Drug Carrier for Biomedical Applications

Albumin, the most abundant protein in plasma, possesses some inherent beneficial structural and physiological characteristics that make it suitable for use as a drug delivery agent, such as an extraordinary drug-binding capacity and long blood retention, with a high biocompatibility. The use of these characteristics as a nanoparticle drug delivery system (DDS) offers several advantages, including a longer circulation time, lower toxicity, and more significant drug loading. To date, many innovative liposome preparations have been developed in which albumin is involved as a DDS. These novel albumin-containing liposome preparations show superior deliverability for genes, hydrophilic/hydrophobic substances and proteins/peptides to the targeting area compared to original liposomes by virtue of their high biocompatibility, stability, effective loading content, and the capacity for targeting. This review summarizes the current status of albumin applications in liposome-based DDS, focusing on albumin-coated liposomes and albumin-encapsulated liposomes as a DDS carrier for potential medical applications.

Delivery of cancer therapies by synthetic and bio-inspired nanovectors

BACKGROUND

As a complement to the clinical development of new anticancer molecules, innovations in therapeutic vectorization aim at solving issues related to tumor specificity and associated toxicities. Nanomedicine is a rapidly evolving field that offers various solutions to increase clinical efficacy and safety. MAIN: Here are presented the recent advances for different types of nanovectors of chemical and biological nature, to identify the best suited for translational research projects. These nanovectors include different types of chemically engineered nanoparticles that now come in many different flavors of 'smart' drug delivery systems. Alternatives with enhanced biocompatibility and a better adaptability to new types of therapeutic molecules are the cell-derived extracellular vesicles and micro-organism-derived oncolytic viruses, virus-like particles and bacterial minicells. In the first part of the review, we describe their main physical, chemical and biological properties and their potential for personalized modifications. The second part focuses on presenting the recent literature on the use of the different families of nanovectors to deliver anticancer molecules for chemotherapy, radiotherapy, nucleic acid-based therapy, modulation of the tumor microenvironment and immunotherapy.

CONCLUSION

This review will help the readers to better appreciate the complexity of available nanovectors and to identify the most fitting "type" for efficient and specific delivery of diverse anticancer therapies.

pH-Sensitive Nanoparticles Composed Solely of Membrane-Disruptive Macromolecules for Treating Pancreatic Cancer

Pancreatic tumor is extremely lethal because its cancerous structures are sheltered by dense stromal barriers that hinder the infiltration of therapeutics. To facilitate the infiltration of therapeutics through the stromal barrier, remodeling the stroma with an adjuvant prior to or together with gemcitabine-the current chemotherapeutic standard for pancreatic cancer-is a widely studied strategy; nevertheless, the intrinsic nonuniformity in distribution (spatial and/or temporal) of the adjuvant and gemcitabine has raised the increased risk of tumor metastasis as a major concern. In this work, we propose long-circulating, pH-sensitive nanoparticles composed solely of cellular membrane-disruptive molecules as a new approach for treating pancreatic cancer. Using a micelle of a polymeric mimetic of host defense peptides as the model for such nanoparticles, we showed that this nanoparticle exhibited acid-activated cytotoxicity indiscriminately to both cancerous and fibroblast cells, and the underlying activity mode was acid-activatable disruption of cellular membrane integrity. As a result, our acid-activatable nanoparticle effectively permeabilized the stromal barrier and eradicated the otherwise sheltered pancreatic cancer cells, as demonstrated with a three-dimensional spheroid in which a shell of fibroblast NIH-3T3 cells was cultured over a core of pancreatic BxPC-3 cells. When administered intravenously into mouse models bearing xenograft pancreatic BxPC-3 tumors, our acid-activatable nanoparticle efficiently inhibited tumor growth without causing noticeable off-target adverse effects or promoting tumor metastasis. Notably, this nanoparticle permeabilized the otherwise dense pancreatic tumor tissue while significantly suppressing the expression of extracellular matrix components and activated cancer-associated fibroblasts. Although the feasibility of our approach was demonstrated with a micelle of a polymeric molecule, we trust that future research efforts in this pathway may eventually offer translational formulations for improving the therapeutic efficacy of pancreatic cancer.

Peptide-functionalized liposomes as therapeutic and diagnostic tools for cancer treatment

Clinically efficacious medication in anticancer therapy has been successfully designed with liposome-based nanomedicine. The liposomal formulation in cancer drug delivery can be facilitated with a functionalized peptide that mediates the specific drug delivery opportunities with increased drug penetrability, specific accumulation in the targeted site, and enhanced therapeutic efficacy. This review aims to focus on recent advances in peptide-functionalized liposomal formulation techniques in cancer diagnosis and treatment regarding recently published literature. It also will highlight different aspects of novel liposomal formulation techniques that incorporate surface functionalization with peptides for better anticancer effect and current challenges in peptide-functionalized liposomal drug formulation.

Designing biotin-human serum albumin nanoparticles to enhance the targeting ability of binuclear ruthenium(III) compound

On the one hand, to obtain a novel next-generation anticancer metal agent; on the other hand, to improve the targeting ability and decrease side effects of metal agent, we proposed to design active-targeting human serum albumin (HSA) nanoparticles (NPs) to achieve the end. Thus, we not only designed and synthesized two ruthenium (Ru) thiosemicarbazone compounds (C1 and C2) but also succeeded in constructing active Biotin-HSA NPs for Ru(III) compounds. Importantly, Biotin-HSA-C2 NPs not only possessed a stronger capacity for killing MCF-7 cells and inhibiting their migration versusC2 alone but also increased accumulation compared to non-malignant WI-38 cells. Additionally, C2 and Biotin-HSA-C2 NPs act against MCF-7 cells by the following potential mechanism: 1) arresting the cell cycle in the S phase by regulating cyclin and cyclin-dependent kinases; 2) inducing apoptosis by releasing cytochrome c to activate caspase-9/3; 3) inhibiting the expression of p-EGFR and regulating its neighboring cellular pathways, followed by the inactivation of PI3K/Akt and activation of p38 MAPK signaling pathways.

Enzyme-Responsive Nanoparticles for Anti-tumor Drug Delivery

The past few decades have seen great progress in the exploration of nanoparticles (NPs) as novel tools for cancer treatments and diagnosis. Practical and reliable application of nanoparticle-based technology in clinical transformation remains nevertheless an ongoing challenge. The design, preparation, and evaluation of various smart NPs with specific physicochemical responses in tumor-related physiological conditions have been of great interests in both academic and clinical research. Of particular, smart enzyme-responsive nanoparticles can predictively and selectively react with specific enzymes expressed in tumor tissues, leading to targeted delivery of anti-tumor drugs, reduced systemic toxicity, and improved therapeutic effect. In addition, NPs interact with internal enzymes usually under mild conditions (low temperature, aqueous media, neutral or close to neutral pH) with high efficiency. In this review, recent advances in the past 5 years in enzyme-responsive nanoparticles for anti-tumor drug delivery are summarized and discussed. The following contents are divided based on the different action sites of enzymes toward NPs, notably hydrophobic core, cleavable/uncleavable linker, hydrophilic crown, and targeting ligand. Enzyme-engaged destruction of any component of these delicate nanoparticle structures could result in either targeting drug delivery or controlled drug release.

The importance of spheroids in analyzing nanomedicine efficacy

The use of nanomedicines for cancer treatment holds a great potential due to their improved efficacy and safety. During the nanomedicine preclinical in vitro evaluation stage, these are mainly tested on cell culture monolayers. However, these 2D models are an unrealistic representation of the in vivo tumors, leading to an inaccurate screening of the candidate formulations. To address this problem, spheroids are emerging as an additional tool to validate the efficacy of new therapeutics due to the ability of these 3D in vitro cancer models to mimic the key features displayed by in vivo solid tumors. In this review, the application of spheroids for the evaluation of nanomedicines' physicochemical properties and therapeutic efficacy is discussed.