Can intracellular drug delivery using hyaluronic acid functionalised pH-sensitive liposomes overcome gemcitabine resistance in pancreatic cancer?

Liposome-enabled bufalin and doxorubicin combination therapy for trastuzumab-resistant breast cancer with a focus on cancer stem cells

Breast cancer stem cells (BCSCs) play a key role in therapeutic resistance in breast cancer treatments and disease recurrence. This study aimed to develop a combination therapy loaded with pH-sensitive liposomes to kill both BCSCs and the okbulk cancer cells using trastuzumab-sensitive and resistant human epidermal growth factor receptor 2 positive (HER2+) breast cancer cell models. The anti-BCSCs effect and cytotoxicity of all-trans retinoic acid, salinomycin, and bufalin alone or in combination with doxorubicin were compared in HER2+ cell line BT-474 and a validated trastuzumab-resistant cell line, BT-474R. The most potent anti-BCSC agent was selected and loaded into a pH-sensitive liposome system. The effects of the liposomal combination on BCSCs and bulk cancer cells were assessed. Compared with BT-474, the aldehyde dehydrogenase positive BCSC population was elevated in BT-474R (3.9 vs. 23.1%). Bufalin was the most potent agent and suppressed tumorigenesis of BCSCs by ∼50%, and showed strong synergism with doxorubicin in both BT-474 and BT-474R cell lines. The liposomal combination of bufalin and doxorubicin significantly reduced the BCSC population size by 85%, and inhibited both tumorigenesis and self-renewal, although it had little effect on the migration and invasiveness. The cytotoxicity against the bulk cancer cells was also enhanced by the liposomal combination than either formulation alone in both cell lines (p < 0.001). The liposomal bufalin and doxorubicin combination therapy may effectively target both BCSCs and bulk cancer cells for a better outcome in trastuzumab-resistant HER2+ breast cancer.

Effect of size and pH-sensitivity of liposomes on cellular uptake pathways and pharmacokinetics of encapsulated gemcitabine

To enhance cytoplasmic delivery efficiency, pH-sensitive liposomes (PSL) have been proposed as a novel strategy. To facilitate clinical translation, this study aims to understand the impact of both size and pH-sensitivity on cellular uptake pathways, intracellular trafficking and pharmacokinetics of liposomes. The large liposomes (130-160 nm) were prepared using thin-film hydration method, while small liposomes (∼60 nm) were fabricated using microfluidics, for both PSL and non-pH-sensitive liposomes (NPSL). Cellular uptake pathways and intracellular trafficking was investigated through confocal imaging with aid of various endocytosis inhibitors. Intracellular gemcitabine delivery by various liposomal formulations was quantified using HPLC, and the cytotoxicity was assessed via cell viability assays. Pharmacokinetics of gemcitabine loaded in various liposomes was evaluated in rats following intravenous administration. Larger liposomes had a higher loading capacity for hydrophilic gemcitabine (7% vs 4%). Small PSL exhibited superior cellular uptake compared to large PSL or NPSLs. Moreover, the alkalization of endosomes significantly attenuated the cellular uptake of PSL. Large liposomes (PSL and NPSL) predominantly entered cells via clathrin-dependent pathway, whereas small liposomes partially utilized caveolae-dependent pathway. However, the long circulation of the liposomes, as measured by the encapsulated gemcitabine, was compromised by both pH-sensitivity and size reduction (9.5 h vs 5.3 h). Despite this drawback, our results indicate that small PSL holds promise as vectors for the next generation of liposomal nanomedicine, owing to their superior cytoplasmic delivery efficiency.

Fine-tuning of liposome integrity for differentiated transcytosis and enhanced antitumor efficacy

Transcytosis-inducing nanomedicines have been developed to improve tumor extravasation. However, the fate during transcytosis across multicell layers and the structural integrity of the nanomedicines before reaching tumor cells could impact antitumor therapy. Here, a BAY 87-2243 (a hypoxia-inducible factor-1 inhibitor)-loaded liposomal system (HA-P-LBAY) modified by low molecular weight protamine (LMWP) and crosslinked by hyaluronic acid (HA) was constructed. This system could accomplish differentiate cellular transport in endothelial and tumor cells by fine-tuning its structural integrity, i.e. transcytosis across the endothelial cells while preserving structural integrity, facilitating subsequent retention and drug release within tumor cells via degradation-induced aggregation. In vitro cellular uptake and transwell studies demonstrated that HA-P-LBAY were internalized by endothelial cells (bEnd.3) via an active, caveolin and heparin sulfate proteoglycan (HSPG)-mediated endocytosis, and subsequently achieved transcytosis mainly through the ER/Golgi pathway. Moreover, the fluorescence resonance energy transfer (FRET) study showed that HA-crosslinking maintained higher integrity of HA-P-LBAY after transcytosis, more efficiently than electrostatic coating of HA (HA/P-LBAY). In addition, more HA-P-LBAY was retained in tumor cells (4T1) compared to HA/P-LBAY corresponding to its enhanced in vitro cytotoxicity. This may be attributed to better integrity of HA-P-LBAY post endothelial transcytosis and more degradation of HA in tumor cells, leading to more liposome aggregation and inhibition of their transcytosis, which was inferred by both TEM images and the HAase responsiveness assay proved by FRET. In vivo, HA-P-LBAY exhibited more potency in tumor suppression than the other formulations in both low and high permeability tumor models. This highlighted that fine-tuning of structural integrity of nanocarriers played a key role no matter whether the transcytosis of nanocarriers contributed to cellular transport. Collectively, this study provides a promising strategy for antitumor therapies by fine-tuning liposome integrity to achieve active trans-endothelial transport with structural integrity and selective aggregation for prolonged tumor retention.

Nanotechnology in medicine revolutionizing drug delivery for cancer and viral infection treatments

Advancements in nanotechnology were vastly applied in medicine and pharmacy, especially in the field of nano-delivery systems. It took a long time for these systems to ensure precise delivery of very delicate molecules, such as RNA, to cells at concentrations that yield remarkable efficiency, with success rates reaching 95.0% and 94.5%. These days, there are several advantages of using nanotechnological solutions in the prevention and treatment of cancer and viral infections. Its interventions improve treatment outcomes both due to increased effectiveness of the drug at target location and by reducing adverse reactions, thereby increasing patient adherence to the therapy. Based on the current knowledge an updated review was made, and perspective, opportunities and challenges in nanomedicine were discussed. The methods employed include comprehensive examination of existing literature and studies on nanoparticles and nano-delivery systems including both in vitro tests performed on cell cultures and in vivo assessments carried out on appropriate animal models, with a specific emphasis on their applications in oncology and virology. This brings together various aspects including both structure and formation as well as its association with characteristic behaviour in organisms, providing a novel perspective. Furthermore, the practical application of these systems in medicine and pharmacy with a focus on viral diseases and malignancies was explored. This review can serve as a valuable guide for fellow researchers, helping them navigate the abundance of findings in this field. The results indicate that applications of nanotechnological solutions for the delivery of medicinal products improving therapeutic outcomes will continue to expand.

Recent Advances in Nanomedicine for Ocular Fundus Neovascularization Disease Management

As an indispensable part of the human sensory system, visual acuity may be impaired and even develop into irreversible blindness due to various ocular pathologies. Among ocular diseases, fundus neovascularization diseases (FNDs) are prominent etiologies of visual impairment worldwide. Intravitreal injection of anti-vascular endothelial growth factor drugs remains the primary therapy but is hurdled by common complications and incomplete potency. To renovate the current therapeutic modalities, nanomedicine emerged as the times required, which is endowed with advanced capabilities, able to fulfill the effective ocular fundus drug delivery and achieve precise drug release control, thus further improving the therapeutic effect. This review provides a comprehensive summary of advances in nanomedicine for FND management from state-of-the-art studies. First, the current therapeutic modalities for FNDs are thoroughly introduced, focusing on the key challenges of ocular fundus drug delivery. Second, nanocarriers are comprehensively reviewed for ocular posterior drug delivery based on the nanostructures: polymer-based nanocarriers, lipid-based nanocarriers, and inorganic nanoparticles. Thirdly, the characteristics of the fundus microenvironment, their pathological changes during FNDs, and corresponding strategies for constructing smart nanocarriers are elaborated. Furthermore, the challenges and prospects of nanomedicine for FND management are thoroughly discussed.

Gemcitabine-Lipid Conjugate and ONC201 Combination Therapy Effectively Treats Orthotopic Pancreatic Tumor-Bearing Mice

Gemcitabine (GEM) is a nucleoside analogue approved as a first line of therapy for pancreatic ductal adenocarcinoma (PDAC). However, rapid metabolism by plasma cytidine deaminase leading to the short half-life, intricate intracellular metabolism, ineffective cell uptake, and swift development of chemoresistance downgrades the clinical efficacy of GEM. ONC201 is a small molecule that inhibits the Akt and ERK pathways and upregulates the TNF-related apoptosis-inducing ligand (TRAIL), which leads to the reversal of both intrinsic and acquired GEM resistance in PDAC treatment. Moreover, the pancreatic cancer cells that were able to bypass apoptosis after treatment of ONC201 get arrested in the G1-phase, which makes them highly sensitive to GEM. To enhance the in vivo stability of GEM, we first synthesized a disulfide bond containing stearate conjugated GEM (lipid-GEM), which makes it sensitive to the redox tumor microenvironment (TME) comprising high glutathione levels. In addition, with the help of colipids 1,2-dioleoyl-glycero-3-phosphocholine (DOPC), cholesterol, and 1,2-distearoyl-glycero-3-phosphoethanolamine-poly(ethylene glycol)-2000 (DSPE-PEG 2000), we were able to synthesize the lipid-GEM conjugate and ONC201 releasing liposomes. A cumulative drug release study confirmed that both ONC201 and GEM showed sustained release from the formulation. Since MUC1 is highly expressed in 70-90% PDAC, we conjugated a MUC1 binding peptide in the liposomes which showed higher cytotoxicity, apoptosis, and cellular internalization by MIA PaCa-2 cells. A biodistribution study further confirmed that the systemic delivery of the liposomes through the tail vein resulted in a higher accumulation of drugs in orthotopic PDAC tumors in NSG mice. The IHC of the excised tumor grafts further confirmed the higher apoptosis and lower metastasis and cell proliferation. Thus, our MUC1 targeting binary drug-releasing liposomal formulation showed higher drug payload, enhanced plasma stability, and accumulation of drugs in the pancreatic orthotopic tumor and thus is a promising therapeutic alternative for the treatment of PDAC.

Conquering chemoresistance in pancreatic cancer: Exploring novel drug therapies and delivery approaches amidst desmoplasia and hypoxia

Pancreatic cancer poses a significant challenge within the field of oncology due to its aggressive behaviour, limited treatment choices, and unfavourable outlook. With a mere 10% survival rate at the 5-year mark, finding effective interventions becomes even more pressing. The intricate relationship between desmoplasia and hypoxia in the tumor microenvironment further complicates matters by promoting resistance to chemotherapy and impeding treatment efficacy. The dense extracellular matrix and cancer-associated fibroblasts characteristic of desmoplasia create a physical and biochemical barrier that impedes drug penetration and fosters an immunosuppressive milieu. Concurrently, hypoxia nurtures aggressive tumor behaviour and resistance to conventional therapies. a comprehensive exploration of emerging medications and innovative drug delivery approaches. Notably, advancements in nanoparticle-based delivery systems, local drug delivery implants, and oxygen-carrying strategies are highlighted for their potential to enhance drug accessibility and therapeutic outcomes. The integration of these strategies with traditional chemotherapies and targeted agents reveals the potential for synergistic effects that amplify treatment responses. These emerging interventions can mitigate desmoplasia and hypoxia-induced barriers, leading to improved drug delivery, treatment efficacy, and patient outcomes in pancreatic cancer. This review article delves into the dynamic landscape of emerging anticancer medications and innovative drug delivery strategies poised to overcome the challenges imposed by desmoplasia and hypoxia in the treatment of pancreatic cancer.

Methotrexate-loaded hyaluronan-modified liposomes integrated into dissolving microneedles for the treatment of psoriasis

Methotrexate (MTX) is a first-line drug in treating psoriasis because of its strong anti-proliferation and anti-inflammatory effects. However, systemic administration of MTX will lead to many side effects, such as gastrointestinal irritation, liver and kidney toxicity, etc. Herein, we developed liposome-loaded microneedles (MNs) system to improve transdermal efficiency, which was used to overcome the problems of low transdermal efficiency and poor therapeutic effect of traditional transdermal drug delivery methods. Hyaluronic acid (HA) was modified on the surface of MTX-loaded liposomes. The interaction of HA and CD44 could increase the adhesion of HA-MTX-Lipo to HaCaT cells, thereby promoting the apoptosis or death of HaCaT cells. Results indicated HA-MTX-Lipo MNs could inhibit the development of psoriasis and reduce the degree of skin erythema, scaling, and thickening. The mRNA levels of proinflammatory cytokines such as IL-17A, IL-23, and TNF-α were decreased. The epidermal thickness and proliferative cell-associated antigen Ki67 expression were also reduced. Specifically, the expression of mRNA levels of proinflammatory cytokines was down-regulated. The MNs transdermal delivery of HA-modified-MTX liposomes provided a promising method for treating psoriasis.

Liposomal nanostructures for Gemcitabine and Paclitaxel delivery in pancreatic cancer

Pancreatic cancer (PC) is an incurable disease with a high death rate in the world nowadays. Gemcitabine (GEM) and Paclitaxel (PTX) are considered as references of chemotherapeutic treatments and are commonly used in clinical applications. Factors related to the tumor microenvironment such as insufficient tumor penetration, toxicity, and drug resistance can limit the effectiveness of these therapeutic anticancer drugs. The use of different liposomal nanostructures is a way that can optimize the drug's effectiveness and reduce toxicity. Given the development of PC therapy, this review focuses on advances in Nano-formulation, characterization, and delivery systems of loaded GEM and PTX liposomes using chemotherapy, nucleic acid delivery, and stroma remodeling therapy. As a result, the review covers the literature dealing with the applications of liposomes in PC therapy.

The bioengineered and multifunctional nanoparticles in pancreatic cancer therapy: Bioresponisive nanostructures, phototherapy and targeted drug delivery

The multidisciplinary approaches in treatment of cancer appear to be essential in term of bringing benefits of several disciplines and their coordination in tumor elimination. Because of the biological and malignant features of cancer cells, they have ability of developing resistance to conventional therapies such as chemo- and radio-therapy. Pancreatic cancer (PC) is a malignant disease of gastrointestinal tract in which chemotherapy and radiotherapy are main tools in its treatment, and recently, nanocarriers have been emerged as promising structures in its therapy. The bioresponsive nanocarriers are able to respond to pH and redox, among others, in targeted delivery of cargo for specific treatment of PC. The loading drugs on the nanoparticles that can be synthetic or natural compounds, can help in more reduction in progression of PC through enhancing their intracellular accumulation in cancer cells. The encapsulation of genes in the nanoparticles can protect against degradation and promotes intracellular accumulation in tumor suppression. A new kind of therapy for cancer is phototherapy in which nanoparticles can stimulate both photothermal therapy and photodynamic therapy through hyperthermia and ROS overgeneration to trigger cell death in PC. Therefore, synergistic therapy of phototherapy with chemotherapy is performed in accelerating tumor suppression. One of the important functions of nanotechnology is selective targeting of PC cells in reducing side effects on normal cells. The nanostructures are capable of being surface functionalized with aptamers, proteins and antibodies to specifically target PC cells in suppressing their progression. Therefore, a specific therapy for PC is provided and future implications for diagnosis of PC is suggested.

Local Sustained Chemotherapy of Pancreatic Cancer Using Endoscopic Ultrasound-Guided Injection of Biodegradable Thermo-Sensitive Hydrogel

Purpose

Endoscopic ultrasound-guided fine-needle injection (EUS-FNI) offers a promising minimally invasive approach for locally targeted management of advanced pancreatic cancer. However, the efficacy is limited due to the rapid plasma clearance of chemotherapeutic agents. Injectable hydrogels can form drug release depots, which provide a feasible solution for optimizing targeted chemotherapy through EUS-FNI.

Methods

A drug delivery system was developed, consisting of gemcitabine (GEM) and thermo-sensitive hydrogel (PLGA-PEG-PLGA, PPP). The injectability, gel formation ability, biocompatibility and sustained drug delivery properties of PPP hydrogel were verified in vitro and in vivo. The effects of GEM/PPP hydrogel on cell proliferation, invasion, metastasis, and apoptosis were explored through co-culturing with PANC-1 cells. The therapeutic effects of GEM/PPP hydrogel on xenograft mice were compared with those of GEM, ethanol and polidocanol using the precisely targeted EUS-FNI technology. Tumor sections were examined by H&E, Ki-67, and TUNEL staining.

Results

GEM/PPP hydrogel exhibited excellent injectability, biocompatibility, and the capability of sustained drug delivery for up to 7 days by forming a gel triggered by body temperature. It demonstrated the best therapeutic effects, significantly reducing proliferation, invasion and migration of PANC-1 cells while promoting apoptosis. After precise injection using EUS-FNI technology, GEM/PPP hydrogel resulted in a reduction of tumor weight by up to 75.96% and extending the survival period by 14.4 days with negligible adverse effects. Pathological examination revealed no systemic toxicity and significant apoptosis and minimal proliferation as well.

Conclusion

The combination of GEM/PPP hydrogel and EUS-FNI technology provides an optimal approach of precise chemotherapy for pancreatic cancer, builds a bridge for clinical translation of basic research, and brings great hope for innovation of minimally invasive treatment modalities. The first-hand EUS image data obtained in this study also serves as a crucial reference for future clinical trials.

Recent Advances in Well-Designed Therapeutic Nanosystems for the Pancreatic Ductal Adenocarcinoma Treatment Dilemma

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with an extremely poor prognosis and low survival rate. Due to its inconspicuous symptoms, PDAC is difficult to diagnose early. Most patients are diagnosed in the middle and late stages, losing the opportunity for surgery. Chemotherapy is the main treatment in clinical practice and improves the survival of patients to some extent. However, the improved prognosis is associated with higher side effects, and the overall prognosis is far from satisfactory. In addition to resistance to chemotherapy, PDAC is significantly resistant to targeted therapy and immunotherapy. The failure of multiple treatment modalities indicates great dilemmas in treating PDAC, including high molecular heterogeneity, high drug resistance, an immunosuppressive microenvironment, and a dense matrix. Nanomedicine shows great potential to overcome the therapeutic barriers of PDAC. Through the careful design and rational modification of nanomaterials, multifunctional intelligent nanosystems can be obtained. These nanosystems can adapt to the environment's needs and compensate for conventional treatments' shortcomings. This review is focused on recent advances in the use of well-designed nanosystems in different therapeutic modalities to overcome the PDAC treatment dilemma, including a variety of novel therapeutic modalities. Finally, these nanosystems' bottlenecks in treating PDAC and the prospect of future clinical translation are briefly discussed.

Liposome-based diagnostic and therapeutic applications for pancreatic cancer

Pancreatic cancer is one of the harshest and most challenging cancers to treat, often labeled as incurable. Chemotherapy continues to be the most popular treatment yet yields a very poor prognosis. The main barriers such as inefficient drug penetration and drug resistance, have led to the development of drug carrier systems. The benefits, ease of fabrication and modification of liposomes render them as ideal future drug delivery systems. This review delves into the versatility of liposomes to achieve various mechanisms of treatment for pancreatic cancer. Not only are there benefits of loading chemotherapy drugs and targeting agents onto liposomes, as well as mRNA combined therapy, but liposomes have also been exploited for immunotherapy and can be programmed to respond to photothermal therapy. Multifunctional liposomal formulations have demonstrated significant pre-clinical success. Functionalising drug-encapsulated liposomes has resulted in triggered drug release, specific targeting, and remodeling of the tumor environment. Suppressing tumor progression has been achieved, due to their ability to more efficiently and precisely deliver chemotherapy. Currently, no multifunctional surface-modified liposomes are clinically approved for pancreatic cancer thus we aim to shed light on the trials and tribulations and progress so far, with the hope for liposomal therapy in the future and improved patient outcomes. STATEMENT OF SIGNIFICANCE: Considering that conventional treatments for pancreatic cancer are highly associated with sub-optimal performance and systemic toxicity, the development of novel therapeutic strategies holds outmost relevance for pancreatic cancer management. Liposomes are being increasingly considered as promising nanocarriers for providing not only an early diagnosis but also effective, highly specific, and safer treatment, improving overall patient outcome. This manuscript is the first in the last 10 years that revises the advances in the application of liposome-based formulations in bioimaging, chemotherapy, phototherapy, immunotherapy, combination therapies, and emergent therapies for pancreatic cancer management. Prospective insights are provided regarding several advantages resulting from the use of liposome technology in precision strategies, fostering new ideas for next-generation diagnosis and targeted therapies of pancreatic cancer.

The role of glutathione conjugation on the transcellular transport process of PEGylated liposomes across the blood brain barrier

Notwithstanding the growing evidence of improved drug delivery efficiency to the brain by ligand modification of PEGylated liposomes, the comprehensive knowledge of their transport processes and payload across the BBB is yet to be revealed. Herein, this study sought to understand the glutathione (GSH) ligand effect on transcellular transport mechanisms of liposomes through the blood-brain barrier (BBB) by comparing PEGylated liposomes (PEG-L) and GSH PEGylated liposomes (GSH-PEG-L). Endocytosis and exocytosis of liposomes including the role of secreted extracellular vesicles (EVs) of brain endothelial cells (BECs) were assessed. Further pharmacokinetics and brain distribution analysis of gemcitabine loaded liposomes were carried in healthy rats to ascertain the in vivo applicability. Our findings suggested that the presence of GSH increased the cellular uptake of liposomes by up to 3-fold in human brain microvascular endothelial cells depending on the dose but not in astrocytes. The cell exposure to liposomes particularly GSH-PEG-L dramatically increased the cell secretion of small and microvesicles with liposomal components, though different liposomes preferred different vesicles for exocytosis. This correlated with GSH-PEG-L transport efficiency of 4% across the in vitro BBB model in 24 h, 1.7-fold higher than that of PEG-L (p < 0.05). In rats, while PEG-L and GSH-PEG-L showed similar pharmacokinetic profiles and prolonged circulation properties, 3.8% of the total injected dose (ID) of gemcitabine was found in the brain of the GSH-PEG-L group at 8 h post-injection, compared with 2.8% ID in the PEG-L group. A brain: blood concentration ratio of 1.27 ± 0.12 indicated that an active transport mechanism to cross the BBB for GSH-PEG-L. Overall, this study revealed that GSH augmented the transcellular transport efficiency of liposomes through BBB to improve targeted brain delivery by enhancing cellular uptake and vesicular exocytosis route of BECs.

A simple approach to re-engineering small extracellular vesicles to circumvent endosome entrapment

Small extracellular vesicles (sEVs) have emerged as attractive drug delivery systems. However, the intracellular release of their cargoes is restricted. This study aimed to develop an efficient approach to re-engineer sEVs by hybridisation with pH-sensitive liposomes (PSLs) and investigate their endosome escape potential. MIA PaCa-2 cell-derived sEVs and PSLs were fused via three methods, and fusion efficiency (FE) was measured using a fluorescence resonance energy transfer assay and nanoparticle tracking analysis. Cellular uptake, intracellular trafficking, and cytotoxicity of doxorubicin-loaded vesicles (Dox@hybrids, Dox@sEVs, and Dox@PSLs) were investigated on MIA PaCa-2 cells. Among the three methods, Ca²⁺-mediated fusion was the simplest and led to a comparable FE with freeze-thaw method, which was significantly higher than PEG₈₀₀₀-mediated fusion. sEVs were more stable after hybridisation with PSLs. Confocal microscopy revealed that the hybrids internalised more efficiently than natural sEVs. While the internalised Dox@sEVs were primarily co-localised with endo/lysosomes even after 8 h, Dox from Dox@hybrids was found to escape from endosomes by 2 h and homogenously distributed in the cytosol before accumulated at nucleus, corresponding to the in vitro pH-responsive release profile. Consequently, Dox@hybrids enhanced cytotoxicity compared with Dox@sEVs, Dox@PSLs, or free drugs. Overall, the biomimetic nanosystem generated by simple Ca²⁺-mediated fusion was more stable and demonstrated higher efficiencies of cellular uptake and endosome escape compared to natural sEVs.

Stimuli-responsive liposomal nanoformulations in cancer therapy: Pre-clinical & clinical approaches

The site-specific delivery of antitumor agents is of importance for providing effective cancer suppression. Poor bioavailability of anticancer compounds and the presence of biological barriers prevent their accumulation in tumor sites. These obstacles can be overcome using liposomal nanostructures. The challenges in cancer chemotherapy and stimuli-responsive nanocarriers are first described in the current review. Then, stimuli-responsive liposomes including pH-, redox-, enzyme-, light-, thermo- and magneto-sensitive nanoparticles are discussed and their potential for delivery of anticancer drugs is emphasized. The pH- or redox-sensitive liposomes are based on internal stimulus and release drug in response to a mildly acidic pH and GSH, respectively. The pH-sensitive liposomes can mediate endosomal escape via proton sponge. The multifunctional liposomes responsive to both redox and pH have more capacity in drug release at tumor site compared to pH- or redox-sensitive alone. The magnetic field and NIR irradiation can be exploited for external stimulation of liposomes. The light-responsive liposomes release drugs when they are exposed to irradiation; thermosensitive-liposomes release drugs at a temperature of >40 °C when there is hyperthermia; magneto-responsive liposomes release drugs in presence of magnetic field. These smart nanoliposomes also mediate co-delivery of drugs and genes in synergistic cancer therapy. Due to lack of long-term toxicity of liposomes, they can be utilized in near future for treatment of cancer patients.

Strategies to enhance drug delivery to solid tumors by harnessing the EPR effects and alternative targeting mechanisms

The Enhanced Permeability and Retention (EPR) effect has been recognized as the central paradigm in tumor-targeted delivery in the last decades. In the wake of this concept, nanotechnologies have reached phenomenal levels in research. However, clinical tumors display a poor manifestation of EPR effect. Factors including tumor heterogeneity, complicating tumor microenvironment, and discrepancies between laboratory models and human tumors largely contribute to poor efficiency in tumor-targeted delivery and therapeutic failure in clinical translation. In this article, approaches for evaluation of EPR effect in human tumor were overviewed as guidance to employ EPR effect for cancer treatment. Strategies to augment EPR-mediated tumoral delivery are discussed in different dimensions including enhancement of vascular permeability, depletion of tumor extracellular matrix and optimization of nanoparticle design. Besides, the recent development in alternative tumor-targeted delivery mechanisms are highlighted including transendothelial pathway, endogenous cell carriers and non-immunogenic bacteria-mediated delivery. In addition, the emerging preclinical models better reflect human tumors are introduced. Finally, more rational applications of EPR effect in other disease and field are proposed. This article elaborates on fundamental reasons for the gaps between theoretical expectation and clinical outcomes, attempting to provide some perspective directions for future development of cancer nanomedicines in this still evolving landscape.

Calcium Enabled Remote Loading of a Weak Acid Into pH-sensitive Liposomes and Augmented Cytosolic Delivery to Cancer Cells via the Proton Sponge Effect

While delivery of chemotherapeutics to cancer cells by nanomedicines can improve therapeutic outcomes, many fail due to the low drug loading (DL), poor cellular uptake and endosomal entrapment. This study investigated the potential to overcome these limitations using pH-sensitive liposomes (PSL) empowered by the use of calcium acetate. An acidic dinitrobenzamide mustard prodrug SN25860 was used as a model drug, with non pH-sensitive liposomes (NPSL) as a reference. Calcium acetate as a remote loading agent allowed to engineer PSL- and NPSL-SN25860 with DL of > 31.1% (w/w). The IC₅₀ of PSL-SN25860 was 21- and 141-fold lower than NPSL and free drug, respectively. At 48 h following injection of PSL-SN25860, NPSL-SN25860 and the free drug, drug concentrations in EMT6-nfsB murine breast tumors were 56.3 µg/g, 6.76 µg/g and undetectable (< 0.015 µg/g), respectively (n = 3). Meanwhile, the ex vivo tumor clonogenic assay showed 9.1%, 19.4% and 42.7% cell survival in the respective tumors. Live-cell imaging and co-localization analysis suggested endosomal escape was accomplished by destabilization of PSL followed by release of Ca²⁺ in endosomes allowing induction of a proton sponge effect. Subsequent endosomal rupture was observed approximately 30 min following endocytosis of PSL containing Ca²⁺. Additionally, calcium in liposomes promoted internalization of both PSL and NPSL. Taken together, this study demonstrated multifaceted functions of calcium acetate in promoting drug loading into liposomes, cellular uptake, and endosomal escape of PSL for efficient cytoplasmic drug delivery. The results shed light on designing nano-platforms for cytoplasmic delivery of various therapeutics.

Evolution of drug delivery systems: From 1950 to 2020 and beyond

Modern drug delivery technology began in 1952 with the advent of the Spansule® sustained-release capsule technology, which can deliver a drug for 12 h after oral administration through an initial immediate dose followed by the remaining released gradually. Until the 1980s, oral and transdermal formulations providing therapeutic durations up to 24 h for small molecules dominated the drug delivery field and the market. The introduction of Lupron Depot® in 1989 opened the door for long-acting injectables and implantables, extending the drug delivery duration from days to months and occasionally years. Notably, the new technologies allowed long-term delivery of peptide and protein drugs, although limited to parenteral administration. The introduction of the first PEGylated protein, Adagen®, in 1990 marked the new era of PEGylation, resulting in Doxil® (doxorubicin in PEGylated liposome) in 1995, Movantik® (PEGylated naloxone - naloxegol) in 2014, and Onpattro® (Patisiran - siRNA in PEGylated lipid nanoparticle) in 2018. Drug-polymer complexes were introduced, e.g., InFed® (iron-dextran complex injection) in 1974 and Abraxane® (paclitaxel-albumin complex) in 2005. In 2000, both Mylotarg™ (antibody-drug conjugate - gemtuzumab ozogamicin) and Rapamune® (sirolimus nanocrystal formulation) were introduced. The year 2000 also marked the launching of the National Nanotechnology Initiative by the U.S. government, which was soon followed by the rest of the world. Extensive work on nanomedicine, particularly formulations designed to escape from endosomes after being taken by tumor cells, along with PEGylation technology, ultimately resulted in the timely development of lipid nanoparticle formulations for COVID-19 vaccine delivery in 2020. While the advances in drug delivery technologies for the last seven decades are breathtaking, they are only the tip of an iceberg of technologies that have yet to be utilized in an approved formulation or even to be discovered. As life expectancy continues to increase, more people require long-term care for various diseases. Filling the current and future unmet needs requires innovative drug delivery technologies to overcome age-old familiar hurdles, e.g., improving water-solubility of poorly soluble drugs, overcoming biological barriers, and developing more efficient long-acting depot formulations. The lessons learned from the past are essential assets for developing future drug delivery technologies implemented into products. As the development of COVID-19 vaccines demonstrated, meeting the unforeseen crisis of the uncertain future requires continuous cumulation of failures (as learning experiences), knowledge, and technologies. Conscious efforts of supporting diversified research topics in the drug delivery field are urgently needed more than ever.

A core-shell nanoplatform as a nonviral vector for targeted delivery of genes to the retina

Retinal diseases, including age-related macular degeneration (AMD), are a major cause of blindness. Efficient delivery of therapeutic genes to retinal cells to treat retinal disease is a formidable challenge. In this study, we developed a core-shell nanoplatform composed of a core and two external layers for targeted delivery of the gene to the retina. The inner core was composed of amino acid-functionalized dendrimers and a nuclear localization signal (NLS) for DNA complexation, nuclear transport and efficient transfection. The inner core was coated in a lipid bilayer that comprised pH-sensitive lipids as the inner shell layer. Hyaluronic acid (HA)-1,2-dioleoylphosphatidylethanolamine (DOPE) as the outermost shell layer was used for retinal cell targeting. This core-shell nanoplatform was developed so that the mobility in the vitreous body of these negatively charged carriers would not be affected by their surface charge, allowing diffusion into the retina, uptake into the retinal cells via CD44-mediated internalization, and finally transport into the nucleus by the NLS. The designed nanoparticles showed safety both in vitro and in vivo and inhibited the expression of VEGF under hypoxia-mimicking conditions. In vitro angiogenesis assays exhibited significant inhibitory effects on cell migration and tube formation. The in vivo assays indicated that this nanoplatform could be delivered to the retina. Taken together, this nanoplatform has the potential to transfer gene material into the retina for the treatment of retinal diseases, including AMD. STATEMENT OF SIGNIFICANCE: It remains a challenge to develop an efficient nonviral vector for gene therapy, especially retinal gene therapy. Various barriers exist in gene delivery and the unique ocular environment, making gene delivery to the retina difficult. In this study, we designed a negatively charged core-shell nanoplatform (HD-NP_PND) for the targeted delivery of gene to the retina. The developed nanoplatform possessed excellent transfection efficiency and safety both in vitro and in vivo. It efficiently delivered a gene to the retina. The results of this study suggested that this core-shell nanoplatform has the potential to deliver genes to the retina to treat retinal diseases, including age-related macular degeneration (AMD).

Nanoencapsulation of Hirudo medicinalis proteins in liposomes as a nanocarrier for inhibiting angiogenesis through targeting VEGFA in the Breast cancer cell line (MCF-7)

Introduction: Breast cancer is the most serious cause of women’s death throughout the world. Using nanocarrier vehicles to the exact site of cancer upgrades the therapeutic efficiency of the drugs. Capsulation of active proteins in the vesicular liposomes’ hydrophilic core is essential to develop a therapeutic protein carrier system. We aimed to encapsulate the medicinal leech saliva extract (LSE) and assess the inhibition of angiogenesis of breast cancer cells by targeting vascular endothelial growth factor A (VEGFA). Methods: In this research, enhanced formulation of liposomal protein was determined by zeta potential analysis, droplet size, drug release assay, and transmission electron microscopy (TEM). Furthermore, a cytotoxicity assay of liposomal LSE was performed to determine the cytotoxic activity of components. For assessing the expression of VEGFA, P53, and hypoxia-inducible factor subunit alpha (HIF1a) genes, Real-Time PCR was applied. Results: Nano liposome was chosen as an enhanced formulation due to its much smaller size (46.23 nm). Liposomal LSE had more practical actions on the MCF-7 cells. As noticed by DAPI staining, apoptosis was extensively greater in treated MCF-7 cells. Wound healing assay demonstrated that MCF-7 cells could not sustain growth at the presence of liposomal LSE and expression of the VEGFA gene was declined in treated cells. Downregulation of VEGFA was evaluated with western blotting technique. Conclusion: It can be concluded that our investigation of the tests confirmed the fact that nano liposomal LSE is a novel promising formulation for anticancer drugs and can significantly improve the penetration of protein drugs to cancer cells.

Droplet Microfluidics for Tumor Drug-Related Studies and Programmable Artificial Cells

Anticancer drug development is a crucial step toward cancer treatment, that requires realistic predictions of malignant tissue development and sophisticated drug delivery. Tumors often acquire drug resistance and drug efficacy, hence cannot be accurately predicted in 2D tumor cell cultures. On the other hand, 3D cultures, including multicellular tumor spheroids (MCTSs), mimic the in vivo cellular arrangement and provide robust platforms for drug testing when grown in hydrogels with characteristics similar to the living body. Microparticles and liposomes are considered smart drug delivery vehicles, are able to target cancerous tissue, and can release entrapped drugs on demand. Microfluidics serve as a high-throughput tool for reproducible, flexible, and automated production of droplet-based microscale constructs, tailored to the desired final application. In this review, it is described how natural hydrogels in combination with droplet microfluidics can generate MCTSs, and the use of microfluidics to produce tumor targeting microparticles and liposomes. One of the highlights of the review documents the use of the bottom-up construction methodologies of synthetic biology for the formation of artificial cellular assemblies, which may additionally incorporate both target cancer cells and prospective drug candidates, as an integrated "droplet incubator" drug assay platform.

Intracellular KRAS-specific antibody enhances the anti-tumor efficacy of gemcitabine in pancreatic cancer by inducing endosomal escape

KRAS mutation is associated with the progression and growth of pancreatic cancer and contributes to chemo-resistance, which poses a significant clinical challenge in pancreatic cancer. Here, we developed a RT22-ep59 antibody (Ab) that directly targets the intracellularly activated GTP-bound form of oncogenic KRAS mutants after it is internalized into cytosol by endocytosis through tumor-associated receptor of extracellular epithelial cell adhesion molecule (EpCAM) and investigated its synergistic anticancer effects in the presence of gemcitabine in pancreatic cancer. We first observed that RT22-ep59 specifically recognized tumor-associated EpCAM and reached the cytosol by endosomal escape. In addition, the anticancer effect of RT22-ep59 was observed in the high-EpCAM-expressing pancreatic cancer cells and gemcitabine-resistant pancreatic cancer cells, but it had little effect on the low-EpCAM-expressing pancreatic cancer cells. Additionally, co-treatment with RT22-ep59 and gemcitabine synergistically inhibited cell viability, migration, and invasion in 3D-cultures and exhibited synergistic anticancer activity by inhibiting the RAF/ERK or PI3K/AKT pathways in cells with high-EpCAM expression. In an orthotopic mouse model, combined administration of RT22-ep59 and gemcitabine significantly inhibited tumor growth. Furthermore, the co-treatment suppressed cancer metastasis by blocking EMT signaling in vitro and in vivo. Our results demonstrated that RT22-ep59 synergistically increased the antitumor activity of gemcitabine by inhibiting RAS signaling by specifically targeting KRAS. This indicates that co-treatment with RT22-ep59 and gemcitabine might be considered a potential therapeutic strategy for pancreatic cancer patients harboring KRAS mutation.

Zebularine suppressed gemcitabine-induced senescence and improved the cellular and plasma pharmacokinetics of gemcitabine, augmented by liposomal co-delivery

Chemoresistance is a major factor driving cancer recurrence. This study investigated the potential of zebularine, a dual cytidine deaminase (CDA)/epigenetic inhibitor, to circumvent gemcitabine-resistance in pancreatic cancer using a nanomedicine co-delivery approach. The mRNA expression of key metabolic enzymes, including CDA for gemcitabine deactivation in a gemcitabine-resistant cell line Gr2000 and its parental MIA PaCa-2 was compared using quantitative reverse transcription polymerase chain reaction. A highly gemcitabine-resistant population (HRP) in Gr2000 were characterised for their growth pattern, β-galactosidase activity (a hallmark of senescence) and chemosensitivity to zebularine after isolation. The CDA inhibition effects of zebularine on the intracellular gemcitabine accumulation and pharmacokinetics in rats when co-delivered with pH-sensitive liposomes (pSL) were investigated. Gr2000 had a 3-time upregulated mRNA expression and enzyme activity for CDA. The HRP (28% of bulk Gr2000) were predominately senescent cells which re-proliferated following a growth arrest for a week. Zebularine suppressed the regrowth of senescent cells, meanwhile enhanced cellular gemcitabine concentration by 2-fold. When co-delivered with pSL, zebularine increased cellular gemcitabine concentration by 4-fold, and extended the half-life of gemcitabine in plasma by 22-fold in rats. In conclusion, multiple mechanisms including therapy-induced senescence were identified with gemcitabine-resistance. Co-delivery of zebularine using liposomes could provide multifaceted benefits in gemcitabine therapy for pancreatic cancer treatment.

Magnetic Fluid Hyperthermia as Treatment Option for Pancreatic Cancer Cells and Pancreatic Cancer Organoids

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) is a cancer with a meager prognosis due to its chemotherapy resistance. A new treatment method may be magnetic fluid hyperthermia (MFH). Magnetoliposomes (ML), consisting of superparamagnetic iron oxide nanoparticles (SPION) stabilized with a phospholipid-bilayer, are exposed to an alternating magnetic field (AMF) to generate heat. To optimize this therapy, we investigated the effects of MFH on human PDAC cell lines and 3D organoid cultures.

MATERIAL AND METHODS

ML cytotoxicity was tested on Mia PaCa-2 and PANC-1 cells and on PDAC 3D organoid cultures, generated from resected tissue of patients. The MFH was achieved by AMF application with an amplitude of 40-47 kA/m and a frequency of 270 kHz. The MFH effect on the cell viability of the cell lines and the organoid cultures was investigated at two different time points. Clonogenic assays evaluated the impairment of colony formation. Altering ML set-ups addressed differences arising from intra- vs extracellular ML locations.

RESULTS

Mia PaCa-2 and PANC-1 cells showed no cytotoxic effects at ML concentrations up to 300 µg(Fe)/mL and 225 µg(Fe)/mL, respectively. ML at a concentration of 225 µg(Fe)/mL were also non-toxic for PDAC organoid cultures. MFH treatment using exclusively extracellular ML presented the highest impact on cell viability. Clonogenic assays demonstrated remarkable impairment as long-term outcome in MFH-treated PDAC cell lines. Additionally, we successfully treated PDAC organoids with extracellular ML-derived MFH, resulting in notably reduced cell viabilities 2h and 24 h post treatment. Still, PDAC organoids seem to partly recover from MFH after 24 h as opposed to conventional 2D-cultures.

CONCLUSION

Treatment with MFH strongly diminished pancreatic cancer cell viability in vitro, making it a promising treatment strategy. As organoids resemble the more advanced in vivo conditions better than conventional 2D cell lines, our organoid model holds great potential for further investigations.

Hyaluronic acid functionalized gold nanorods combined with copper-based therapeutic agents for chemo-photothermal cancer therapy

We herein report a hybrid nanocomposite (AuNRs-CTN@THA) which is based on hyaluronic acid-coated gold nanorods with loading of a copper complex through strong bonds. AuNRs-CTN@THA exhibits durable photothermal conversion capacity for pH-dominant and pH/temperature dual sensitive drug release, accomplishing synergetic antitumor efficacy and deep tumor penetration.

Recent Advances in Lipid-Based Nanosystems for Gemcitabine and Gemcitabine-Combination Therapy

The anti-metabolite drug gemcitabine is widely used for the treatment of a variety of cancers. At present, gemcitabine is administered as a hydrochloride salt that is delivered by slow intravenous injection in cycles of three or four weeks. Although regarded as a 'front-line' chemotherapeutic agent, its efficacy is hampered by poor target cell specificity, sub-optimal cellular uptake, rapid clearance from circulation, the development of chemoresistance, and undesirable side-effects. The use of organic, inorganic, and metal-based nanoparticles as delivery agents presents an opportunity to overcome these limitations and safely harness optimal drug efficacy and enhance their therapeutic indices. Among the many and varied nano delivery agents explored, the greatest body of knowledge has been generated in the field of lipid-mediated delivery. We review here the liposomes, niosomes, solid lipid nanoparticles, nanostructured lipid carriers, exosomes, lipid-polymer hybrids, and other novel lipid-based agents that have been developed within the past six years for the delivery of gemcitabine and its co-drugs.

Gefitinib encapsulation based on nano-liposomes for enhancing the curative effect of lung cancer

Gefitinib (GEB) is one of the drugs used for patients with epidermal growth factor receptor (EGFR)-positive mutations in non-small cell lung cancer (NSCLC). However, application of GEB is limited by its low water solubility, stability, and utilization rate, especially the side effects while GEB is given by oral. In this study, nanoliposome was used as a carrier to prepare nanoliposome compound drug (GL) by embedding GEB in the nanoliposome perfectly combined with green nontoxic solvent and thin-film dispersion method. The nanoliposome structure was expected to improve the water solubility and biocompatibility of GEB, thus improving the effect of cancer treatment. The surface electronegative nanoliposomes can effectively avoid protein adsorption and prolong the circulation time in vivo. Meanwhile, the ratio of lecithin to cholesterol (LE/CH) was explored to maximize the encapsulation efficiency of nanoliposome. Subsequent test results showed that GL exhibited better stability, smaller particle size and higher encapsulation efficiency. In addition, in vitro drug release curve also further confirmed that GL had a promising drug sustained-release effect. In particular, a series of in vitro tests such as cell activity, apoptosis, colony formation, scratch, invasion, and cell cycle assays were performed. The results indicated that GL significantly enhanced the pro-apoptotic effect on A549 cells. Most cell cycles of A549 cells were blocked in the G0/G1 phase influenced by GL, thus inhibiting the proliferation of cancer cells. In vivo anti-tumor studies showed that compared with pure GEB, GL had a significant inhibiting effect on NSCLC. In conclusion, the GL which was synthesized by a simple method in this study significantly improved the treatment effect of cancer cells, which proved that the nanoliposome carrier had an excellent application prospect in the treatment of lung cancer.

Combined treatment of mitoxantrone sensitizes breast cancer cells to rapalogs through blocking eEF-2K-mediated activation of Akt and autophagy

Oncogenic activation of the mTOR signaling pathway occurs frequently in tumor cells and contributes to the devastating features of cancer, including breast cancer. mTOR inhibitors rapalogs are promising anticancer agents in clinical trials; however, rapalogs resistance remains an unresolved clinical challenge. Therefore, understanding the mechanisms by which cells become resistant to rapalogs may guide the development of successful mTOR-targeted cancer therapy. In this study, we found that eEF-2K, which is overexpressed in cancer cells and is required for survival of stressed cells, was involved in the negative-feedback activation of Akt and cytoprotective autophagy induction in breast cancer cells in response to mTOR inhibitors. Therefore, disruption of eEF-2K simultaneously abrogates the two critical resistance signaling pathways, sensitizing breast cancer cells to rapalogs. Importantly, we identified mitoxantrone, an admitted anticancer drug for a wide range of tumors, as a potential inhibitor of eEF-2K via a structure-based virtual screening strategy. We further demonstrated that mitoxantrone binds to eEF-2K and inhibits its activity, and the combination treatment of mitoxantrone and mTOR inhibitor resulted in significant synergistic cytotoxicity in breast cancer. In conclusion, we report that eEF-2K contributes to the activation of resistance signaling pathways of mTOR inhibitor, suggesting a novel strategy to enhance mTOR-targeted cancer therapy through combining mitoxantrone, an eEF-2K inhibitor.

Lipid-based Nanoplatforms in Cancer Therapy: Recent Advances and Applications

Though modern available cancer therapies are effective, they possess major adverse effects, causing non-compliance to patients. Furthermore, the majority of the polymeric-based medication platforms are certainly not universally acceptable, due to their several restrictions. With this juxtaposition, lipid-based medication delivery systems have appeared as promising drug nanocarriers to replace the majority of the polymer-based products because they are in a position to reverse polymer as well as, drug-associated restrictions. Furthermore, the amalgamation of the basic principle of nanotechnology in designing lipid nanocarriers, which are the latest form of lipid carriers, has tremendous chemotherapeutic possibilities as tumor-targeted drug-delivery pertaining to tumor therapy. Apart from this, it is reported that nearly 40% of the modern medication entities are lipophilic. Moreover, research continues to be efficient in attaining a significant understanding of the absorption and bioavailability of the developed lipids systems.

Pharmacokinetic and Pharmacodynamic Evaluation of Resveratrol Loaded Cationic Liposomes for Targeting Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. The destructive nature of the disease makes it difficult for clinicians to manage the condition. Hence, there is an urgent need to find new alternatives for HCC, as the role of conventional cytotoxic drugs has reached a plateau to control HCC associated mortality. Antioxidant compounds of plant origin with potential anti-tumor effect have been recognized as alternate modes in cancer treatment and chemoprevention. Resveratrol (RS) is a model natural nonflavonoid drug known for its anti-cancer activity. However, its clinical application is limited due to its poor bioavailability. The current research work aims to formulate, optimize, and characterize RS loaded cationic liposomes (RLs) for specific delivery in HCC. The optimized liposomes formulation (RL5) was spherical with a vesicle size (VS) of 145.78 ± 9.9 nm, ζ potential (ZP) of 38.03 ± 9.12 mV, and encapsulation efficiency (EE) of 78.14 ± 8.04%. In vitro cytotoxicity studies in HepG2 cells demonstrated an improved anti-cancer activity of RL5 in comparison with free RS. These outcomes were supported by a cell uptake study in HepG2 cells, in which RL5 exhibited a higher uptake than free RS. Furthermore, confocal images of HepG2 cells after 3 and 5 h of incubation showed higher internalization of coumarin 6 (C6) loaded liposomes (CL) as compared to those of the free C6. Pharmacokinetic and pharmacodynamic (prophylactic and therapeutic treatment modalities) studies were performed in N-nitrosodiethylamine (NDEA-carcinogen) induced HCC in rats. Pharmacokinetic evaluation of RL5 demonstrated increased localization of RS in cancerous liver tissues by 3.2- and 2.2-fold increase in AUC and Cmax, respectively, when compared to those of the free RS group. A pharmacodynamic investigation revealed a significant reduction in hepatocyte nodules in RL5 treated animals when compared to those of free RS. Further, on treatment with RL5, HCC-bearing rats showed a significant decrease in the liver marker enzymes (alanine transaminase, alkaline phosphatase, aspartate transaminase, total bilirubin levels, γ-glutamyl transpeptidase, and α-fetoprotein), in comparison with that of the disease control group. Our findings were supported by histopathological analysis, and we were first to demonstrate that NDEA induced detrimental effect on rat livers was successfully reversed with the treatment of RL5 formulation. These results implied that delivery of RS loaded cationic liposomes substantially controlled the severity of HCC and that they can be considered as a promising nanocarrier in the management of HCC.

Developmental Strategies of Curcumin Solid Dispersions for Enhancing Bioavailability

BACKGROUND

Although curcumin has been demonstrated to be beneficial in treating various diseases, its low solubility, chemical stability and bioavailability limit its application, especially in cancer therapy.

METHODS

Solid dispersions have been utilized in the last few decades to improve the bioavailability and stability of curcumin.

RESULTS

However, there is a lack of summaries and classifications of the methods for preparing curcumin with this technology. The current review aims to overview the strategies used to develop solid dispersions containing curcumin for improving drug delivery. The classification of techniques for creating solid dispersions for curcumin was summarized, including systems for protecting curcumin degradation despite its chemical stability. The applications of advanced nanotechnologies in recent studies of solid dispersions were also discussed to explain the roles of nanoparticles in formulations.

CONCLUSION

This overview of recent developments in formulating solid dispersions for improving curcumin bioavailability will contribute to future studies of curcumin for clinical development.

Effective Transcutaneous Delivery of Hyaluronic Acid Using an Easy-to-Prepare Reverse Micelle Formulation

The skin loses its moisture with advancing age, causing cosmetic issues such as wrinkles. In addition, the loss of moisture leads to hypersensitivity to external stimuli such as UV light. Transcutaneous supplementation with hyaluronic acid (HA) is an effective and safe method of recovering the moisturizing function and elasticity of the skin. However, the transcutaneous delivery of HA remains challenging owing to the barrier function of the stratum corneum (SC) layer. To penetrate the SC barrier, we used a reverse micelle formulation that does not require high energy consumption processes for preparation. We aimed to enhance the skin permeability of HA by incorporating glyceryl monooleate—a skin permeation enhancer—into the formulation. A fluorescently-labeled HA-loaded reverse micelle formulation showed significantly enhanced permeation across Yucatan micro pig skin. Fourier transform infra-red spectroscopy of the surface of the skin treated with the reverse micelle formulation showed blue shifts of the CH2 symmetric/asymmetric stretching peaks, indicating a reduction in the barrier function of the SC. Further study revealed that HA was released from the reverse micelles at the hydrophobic/hydrophilic interface between the SC and the living epidermis. The results demonstrated that our reverse micellar system is an easy-to-prepare formulation for the effective transcutaneous delivery of HA.

PCC0208023, a potent SHP2 allosteric inhibitor, imparts an antitumor effect against KRAS mutant colorectal cancer

The non-receptor tyrosine phosphatase SHP2, encoded by PTPN11, plays an indispensable role in tumors driven by oncogenic KRAS mutations, which frequently occur in colorectal cancer. Here, PCC0208023, a potent SHP2 allosteric inhibitor, was synthesized to evaluate its inhibitory effects against the SHP2 enzyme, and the KRAS mutant colorectal cancer in vitro and in vivo, and its impart on the RAS/MAPK pathway. Consistent with an allosteric mode of inhibition, PCC0208023 can non-competitively inhibit the activity of full-length SHP2 enzyme, but lacks activity against the free catalytic domain of SHP2. Furthermore, PCC0208023 inhibited the proliferation of KRAS mutation-driven human colorectal cancer cells by inhibiting the RAS/MAPK signaling pathway in vitro. Importantly, PCC0208023 displayed good anti-tumor efficacy against KRAS-driven LS180 and HCT116 xenograft models in nude mice with the decreased Ki67 and p-ERK level, and increased cleaved caspase-3 expression in tumors. Interestingly, PCC0208023 maintained high levels in LS180 tumors within 24 h after administration and was mainly distributed in both intestines and lungs. Molecular docking studies revealed a higher affinity of PCC0208023 with key residues in the SHP2 allosteric pocket than RMC-4550. PCC0208023 deserves further optimization to identify additional low-toxic and potent SHP2 allosteric inhibitors with novel scaffolds for the treatment of patients with KRAS mutation-positive colorectal cancer.