Tumor Microenvironment-Induced Drug Depository for Persistent Antitumor Chemotherapy and Immune Activation.

Herein, a drug-loading nanosystem that can in situ form drug depository for persistent antitumor chemotherapy and immune regulation is designed and built. The system (DOX@MIL-LOX@AL) is fabricated by packaging alginate on the surface of Doxorubicin (DOX) and lactate oxidase (LOX) loaded MIL-101(Fe)-NH2 nanoparticle, which can easily aggregate in the tumor microenvironment through the cross-linking with intratumoral Ca2+. Benefiting from the tumor retention ability, the fast-formed drug depository will continuously release DOX and Fe ions through the ATP-triggered slow degradation, thus realizing persistent antitumor chemotherapy and immune regulation. Meanwhile, LOX in the non-aggregated nanoparticles is able to convert the lactic acid to H2O2, which will be subsequently decomposed into ·OH by Fe ions to further enhance the DOX-induced immunogenic death effect of tumor cells. Together, with the effective consumption of immunosuppressive lactic acid, long-term chemotherapy, and oxidation therapy, DOX@MIL-LOX@AL can execute high-performance antitumor chemotherapy and immune activation with only one subcutaneous administration.

Lipid nanoparticle-mediated codelivery of Cas9 mRNA and single-guide RNA achieves liver-specific in vivo genome editing of Angptl3.

Loss-of-function mutations in Angiopoietin-like 3 (Angptl3) are associated with lowered blood lipid levels, making Angptl3 an attractive therapeutic target for the treatment of human lipoprotein metabolism disorders. In this study, we developed a lipid nanoparticle delivery platform carrying Cas9 messenger RNA (mRNA) and guide RNA for CRISPR-Cas9-based genome editing of Angptl3 in vivo. This system mediated specific and efficient Angptl3 gene knockdown in the liver of wild-type C57BL/6 mice, resulting in profound reductions in serum ANGPTL3 protein, low density lipoprotein cholesterol, and triglyceride levels. Our delivery platform is significantly more efficient than the FDA-approved MC-3 LNP, the current gold standard. No evidence of off-target mutagenesis was detected at any of the nine top-predicted sites, and no evidence of toxicity was detected in the liver. Importantly, the therapeutic effect of genome editing was stable for at least 100 d after a single dose administration. This study highlights the potential of LNP-mediated delivery as a specific, effective, and safe platform for Cas9-based therapeutics.

Intranasal administration of innovative triamcinolone acetonide encapsulated cubosomal in situ gel: formulation and characterization.

AIM: The primary objective of the research was to develop a cubosomal in situ gel encapsulated with Triamcinolone acetonide (TCA) in order to enhance its penetration through the blood-brain barrier (BBB) when administered via the intranasal route, thus enabling efficient and rapid action. METHOD: Cubosomes were formulated by top-down approach using glyceryl monooleate (GMO), using pluronics127 (PF127) and polyvinyl alcohol (PVA) in varying proportions based on the Box-Behnken design. High resolution transmission electron microscopy (HR-TEM) analysis confirmed the morphology of the cubosomes. The in situ gel was formulated and optimized. Experiments involving ex vivo permeation and histopathology analyses were undertaken to evaluate drug permeation and tissue effects. RESULTS: The cubosomes exhibited a particle size (PS) of 197.9 nm, zeta potential (ZP) of -31.11 mV, and entrapment efficacy (EE) of 84.31%, with low deviation. Batch F4 (19% PF127) showed favorable results. In vitro and ex vivo permeation studies revealed drug release of 78.59% and 76.65%, respectively, after 8 h. Drug release followed the Hixson Crowell model of release kinetics. The histopathological examination revealed no signs of toxicity or adverse effects on the nasal mucosa of the sheep. The formulation exhibited short-term stability, maintaining its integrity and properties when stored at room temperature. CONCLUSION: The utilization of an intranasal cubosomal in situ gel encapsulated with TCA was anticipated to lower intracranial pressure and improve patient adherence by offering effective relief for individuals suffering from Brain edema. This efficacy is attributed to its rapid onset of action and its safe and well-tolerated dosage form.

Quality by design endorsed atorvastatin-loaded nanostructured lipid carriers embedded in pH-responsive gel for melanoma.

AIM: Our aim was to repurpose atorvastatin for melanoma by encapsulating in a nanostructured lipid carrier matrix to promote tumour cell internalisation and skin permeation. pH-responsive chitosan gel was employed to restrict At-NLCs in upper dermal layers. METHODS: We utilised a quality by design approach for encapsulating At within the NLC matrix. Further, cellular uptake and cytotoxicity was evaluated along with pH-responsive release and ex vivo skin permeation. RESULTS: Cytotoxicity assay showed 3.13-fold enhanced cytotoxicity on melanoma cells compared to plain drug with nuclear staining showing apoptotic markers. In vitro, release studies showed 5.9-fold rapid release in chitosan gel matrix at pH 5.5 compared to neutral pH. CONCLUSIONS: At-NLCs prevented precipitation, promoted skin permeation, and SK-MEL 28 cell internalisation. The localisation of NLCs on the upper dermal layer due to electrostatic interactions of skin with chitosan gel diminished the incidence of untoward systemic effects.

Polymer Nanoparticles with 2-HP-ß-Cyclodextrin for Enhanced Retention of Uptake into HCE-T Cells.

Triamcinolone acetonide (TA), a medium-potency synthetic glucocorticoid, is primarily employed to treat posterior ocular diseases using vitreous injection. This study aimed to design novel ocular nanoformulation drug delivery systems using PLGA carriers to overcome the ocular drug delivery barrier and facilitate effective delivery into the ocular tissues after topical administration. The surface of the PLGA nanodelivery system was made hydrophilic (2-HP-ß-CD) through an emulsified solvent volatilization method, followed by system characterization. The mechanism of cellular uptake across the corneal epithelial cell barrier used rhodamine B (Rh-B) to prepare fluorescent probes for delivery systems. The triamcinolone acetonide (TA)-loaded nanodelivery system was validated by in vitro release behavior, isolated corneal permeability, and in vivo atrial hydrodynamics. The results indicated that the fluorescent probes, viz., the Rh-B-(2-HP-ß-CD)/PLGA NPs and the drug-loaded TA-(2-HP-ß-CD)/PLGA NPs, were within 200 nm in size. Moreover, the system was homogeneous and stable. The in vitro transport mechanism across the epithelial barrier showed that the uptake of nanoparticles was time-dependent and that NPs were actively transported across the epithelial barrier. The in vitro release behavior of the TA-loaded nanodelivery systems revealed that (2-HP-ß-CD)/PLGA nanoparticles could prolong the drug release time to up to three times longer than the suspensions. The isolated corneal permeability demonstrated that TA-(2-HP-ß-CD)/PLGA NPs could extend the precorneal retention time and boost corneal permeability. Thus, they increased the cumulative release per unit area 7.99-fold at 8 h compared to the suspension. The pharmacokinetics within the aqueous humor showed that (2-HP-ß-CD)/PLGA nanoparticles could elevate the bioavailability of the drug, and its Cmax was 51.91 times higher than that of the triamcinolone acetonide aqueous solution. Therefore, (2-HP-ß-CD)/PLGA NPs can potentially elevate transmembrane uptake, promote corneal permeability, and improve the bioavailability of drugs inside the aqueous humor. This study provides a foundation for future research on transocular barrier nanoformulations for non-invasive drug delivery.

Integrated multi-omics analysis reveals unique signatures of paclitaxel-loaded poly(lactide-co-glycolide) nanoparticles treatment of head and neck cancer cells.

The use of poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) as carriers for chemotherapeutic drugs is regarded as an actively targeted nano-therapy for the specific delivery of anti-cancer drugs to target cells. However, the exact mechanism by which PLGA NPs boost anticancer cytotoxicity at the molecular level remains largely unclear. This study employed different molecular approaches to define the response of carcinoma FaDu cells to different types of treatment, specifically: paclitaxel (PTX) alone, drug free PLGA NPs, and PTX-loaded PTX-PLGA NPs. Functional cell assays revealed that PTX-PLGA NPs treated cells had a higher level of apoptosis than PTX alone, whereas the complementary, UHPLC-MS/MS (TIMS-TOF) based multi-omics analyses revealed that PTX-PLGA NPs treatment resulted in increased abundance of proteins associated with tubulin, as well as metabolites such as 5-thymidylic acid, PC(18:1(9Z)/18:1(9Z0), vitamin D, and sphinganine among others. The multi-omics analyses revealed new insights about the molecular mechanisms underlying the action of novel anticancer NP therapies. In particular, PTX-loaded NPs appeared to exacerbate specific changes induced by both PLGA-NPs and PTX as a free drug. Hence, the PTX-PLGA NPs' molecular mode of action, seen in greater detail, depends on this synergy that ultimately accelerates the apoptotic process, resulting in cancer cell death.

Melt Polycondensation Strategy for Amide-Functionalized l-Aspartic Acid Amphiphilic Polyester Nano-assemblies and Enzyme-Responsive Drug Delivery in Cancer Cells.

Aliphatic polyesters are intrinsically enzymatic-biodegradable, and there is ever-increasing demand for safe and smart next-generation biomaterials including drug delivery nano-vectors in cancer research. Using bioresource-based biodegradable polyesters is one of the elegant strategies to meet this requirement; here, we report an l-amino acid-based amide-functionalized polyester platform and explore their lysosomal enzymatic biodegradation aspects to administrate anticancer drugs in cancer cells. l-Aspartic acid was chosen and different amide-side chain-functionalized di-ester monomers were tailor-made having aromatic, aliphatic, and bio-source pendant units. Under solvent-free melt polycondensation methodology; these monomers underwent polymerization to yield high molecular weight polyesters with tunable thermal properties. PEGylated l-aspartic monomer was designed to make thermo-responsive amphiphilic polyesters. This amphiphilic polyester was self-assembled into a 140 ± 10 nm-sized spherical nanoparticle in aqueous medium, which exhibited lower critical solution temperature at 40-42 °C. The polyester nano-assemblies showed excellent encapsulation capabilities for anticancer drug doxorubicin (DOX), anti-inflammatory drug curcumin, biomarkers such as rose bengal (RB), and 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt. The amphiphilic polyester NP was found to be very stable under extracellular conditions and underwent degradation upon exposure to horse liver esterase enzyme in phosphate-buffered saline at 37 °C to release 90% of the loaded cargoes. Cytotoxicity studies in breast cancer MCF 7 and wild-type mouse embryonic fibroblasts cell lines revealed that the amphiphilic polyester was non-toxic to cell lines up to 100 µg/mL, while their drug-loaded polyester nanoparticles were able to inhibit the cancerous cell growth. Temperature-dependent cellular uptake studies further confirmed the energy-dependent endocytosis of polymer NPs across the cellular membranes. Confocal laser scanning microscopy assisted time-dependent cellular uptake analysis directly evident for the endocytosis of DOX loaded polymer NP and their internalization for biodegradation. In a nutshell, the present investigation opens up an avenue for the l-amino acid-based biodegradable polyesters from l-aspartic acids, and the proof of concept is demonstrated for drug delivery in the cancer cell line.

Advanced multifunctional nano-lipid carrier loaded gel for targeted delivery of 5-flurouracil and cannabidiol against non-melanoma skin cancer.

Non-melanoma skin cancer is one of the most common malignancies reported around the globe. Current treatment therapies fail to meet the desired therapeutic efficacy due to high degree of drug resistance. Thus, there is prominent demand in advancing the current conventional therapy to achieve desired therapeutic efficacy. To break the bottleneck, nanoparticles have been used as next generation vehicles that facilitate the efficient interaction with the cancer cells. Here, we developed combined therapy of 5-fluorouracil (5-FU) and cannabidiol (CBD)-loaded nanostructured lipid carrier gel (FU-CBD-NLCs gel). The current investigation has been designed to evaluate the safety and efficacy of developed 5-Flurouracil and cannabidiol loaded combinatorial lipid-based nanocarrier (FU-CBD NLCs) gel for the effective treatment of skin cancer. Initially, confocal microscopy study results showed excellent uptake and deposition at epidermal and the dermal layer. Irritation studies performed by IR camera and HET cam shows FU-CBD NLCs was much more tolerated and less irritant compared to conventional treatment. Furthermore, gamma scintigraphy evaluation shows the skin retention behavior of the formulation. Later, in-ovo tumor remission studies were performed, and it was found that prepared FU-CBD NLCs was able to reduce tumor volume significantly compared to conventional formulation. Thus, obtained results disclosed that permeation and disposition of 5-FU and CBD into different layers of the skin FU-CBD NLCs gel could be more potential carrier than conventional gel. Furthermore, prepared formulation showed greater tumor remission, better survival rate, reduction in tumor number, area, and volume with improved biochemical profile. Thus, prepared gel could serve as a promising formulation approach for the skin cancer treatment.

Evaluation of drug carrier hepatotoxicity using primary cell culture models.

This study aims to establish a primary rat hepatocyte culture model to evaluate dose-dependent hepatotoxic effects of drug carriers (lipopolymer nanoparticles; LPNs) temporal. Primary rat hepatocyte cell cultures were used to determine half-maximal Inhibition Concentrations (IC50) of the drug-carrier library. Drug-carrier library, at concentrations <50 µg/mL, is benign to primary rat hepatocytes as determined using albumin and urea secretions. Albumin, as a hepatic biomarker, exhibited a more sensitive and faster outcome, compared to urea, for the determination of the IC50 value of LPNs. Temporal measurements of hepatic biomarkers including urea and albumin, and rigorous physicochemical (hydrodynamic diameter, surface charge, etc.) characterization, should be combined to evaluate the hepatotoxicity of drug carrier libraries in screens.

A transfersomes hydrogel patch for cutaneous delivery of propranolol hydrochloride: formulation, in vitro, ex vivo and in vivo studies.

OBJECTIVE: In this work, a propranolol hydrochloride (PRH) transfersomes loaded cutaneous hydrogel patch was developed for topical drug delivery in the affected area of infantile haemangioma. METHODS: Sodium cholate was used as the edge activator to prepare the transfersomes. Based on the central composite design, transfersomes hydrogel patch formulation was optimised with 48 h cumulative penetration and time lag as response values. Particle sizes and morphology of the prepared transfersomes were assessed. They were loaded in a cutaneous hydrogel patch, after which their skin permeation abilities were evaluated, and histopathological effects were investigated using guinea pigs. Moreover, in vivo pharmacokinetics studies were performed in rats. RESULTS: The transfersomes system had a encapsulation efficiency of 81.84 ± 0.53%, particle size of 186.8 ± 3.38 nm, polydispersity index of 0.186 ± 0.002, and a zeta potential of -28.6 ± 2.39 mV. Transmission electron microscopy images revealed sphericity of the particles. The ex vivo drug's penetration of the optimised transfersomes hydrogel patch was 111.05 ± 11.97 µg/cm2 through rat skin within 48 h. Assessment of skin tissue did not reveal any histopathological alterations in epidermal and dermal cells. Pharmacokinetic studies showed that skin Cmax (68.22 µg/cm2) and AUC0-24 (1007.33 µg/cm2 × h) for PRH transfersomes hydrogel patch were significantly higher than those of commercially available oral dosage form and hydrogel patch without transfersomes. These findings imply that the transfersomes hydrogel patch can prolong drug accumulation in the affected skin area, and reduce systemic drug distribution via the blood stream. CONCLUSIONS: The hydrogel patch-loaded PRH transfersomes is a potentially useful drug formulation for infantile haemangioma.

Multifunctional nanoparticles encapsulating methotrexate and curcumin for holistic management of rheumatoid arthritis: in-vitro and pre-clinical assessment.

PURPOSE: Bovine serum albumin (BSA) nanoparticles (BSA-MTX-CUR-NPs) encapsulating methotrexate (MTX) and curcumin (CUR) was developed with an aim to co-deliver the drugs at the inflamed joint so as to maximize the therapeutic efficacy and alleviate toxic side effects associated with MTX. METHODS: Nanoparticle albumin-bound technology was used to formulate nanoparticles, followed by characterization for its particle size, polydispersity index, encapsulation efficiency, zeta potential, surface morphology, in-vitro drug release and drug release kinetics. Further, we investigated the pharmacokinetics and pharmacodynamics of the developed nanoparticles in the adjuvant-induced arthritis model. RESULTS: BSA-MTX-CUR-NPs exhibited particle size of 163.05 ± 1.708 nm, polydispersity index of 0.195 ± 0.0024 and % encapsulation efficiency of 68.23 ± 0.640% for MTX and 75.71 ± 0.216% for CUR with controlled release pattern for both the drugs. The scanning electron microscopy revealed nanoparticles exhibited a spherical shape. DSC study confirmed the absence of incompatibility between the drugs and the excipients. Half-life and area under the curve were significantly higher for MTX in the nanoparticulate form in comparison to free MTX. Pharmacodynamic studies revealed that BSA-MTX-CUR-NPs possessed better disease-modifying effects in comparison to free MTX. CONCLUSION: Hence, it can be concluded that albumin nanoparticles constitute a viable method for delivering MTX and CUR to inflamed joints simultaneously, because of the strong affinity of albumin and enhanced permeability and retention effect at the inflamed joint. This combinational therapy of MTX & CUR in nanoparticulate form has the potential for the holistic management of rheumatoid arthritis.

Novel Cocktail Therapy Based on a Nanocarrier with an Efficient Transcytosis Property Reverses the Dynamically Deteriorating Tumor Microenvironment for Enhanced Immunotherapy.

The immune checkpoint blockade (ICB) faces a low response rate in clinical cancer treatment. Chemotherapy could enhance the response rate of the ICB, but patients would suffer from side effects. The off-target toxicity could be reduced by loading the chemotherapeutic agent through nanocarriers. Therefore, we developed a polymeric carrier for doxorubicin (DOX) loading to form DOX nanoparticles (DOX NPs), which were spatiotemporally responsive to the tumor microenvironment (TME). DOX NPs had an efficient transcytosis property for deep tumor infiltration and sustained drug release ability. Unfortunately, a binary therapy of DOX NPs and ICB induces tumor adaptive resistance and causes dynamic deterioration of the TME. We propose for the first time that TGF-ß1 is a major cause of tumor adaptive resistance and developed an immune cocktail therapy containing DOX NPs, ICB, and TGF-ß1 gene silencing nanoparticles. This therapy successfully overcame tumor adaptive resistance by reversing the immunosuppressive TME and achieved enhanced tumor treatment efficiency.

QbD-Optimized, Phospholipid-Based Elastic Nanovesicles for the Effective Delivery of 6-Gingerol: A Promising Topical Option for Pain-Related Disorders.

In this study, elastic nanovesicles, constructed of phospholipids optimized by Quality by Design (QbD), release 6-gingerol (6-G), a natural chemical that may alleviate osteoporosis and musculoskeletal-related pain. A 6-gingerol-loaded transfersome (6-GTF) formulation was developed using a thin film and sonication approach. 6-GTFs were optimized using BBD. Vesicle size, PDI, zeta potential, TEM, in vitro drug release, and antioxidant activity were evaluated for the 6-GTF formulation. The optimized 6-GTF formulation had a 160.42 nm vesicle size, a 0.259 PDI, and a -32.12 mV zeta potential. TEM showed sphericity. The 6-GTF formulation's in vitro drug release was 69.21%, compared to 47.71% for the pure drug suspension. The Higuchi model best described 6-G release from transfersomes, while the Korsmeyer-Peppas model supported non-Fickian diffusion. 6-GTF had more antioxidant activity than the pure 6-G suspension. The optimized transfersome formulation was converted into a gel to improve skin retention and efficacy. The optimized gel had a spreadability of 13.46 ± 4.42 g·cm/s and an extrudability of 15.19 ± 2.01 g/cm2. The suspension gel had a 1.5 µg/cm2/h ex vivo skin penetration flux, while the 6-GTF gel had 2.71 µg/cm2/h. Rhodamine B-loaded TF gel reached deeper skin layers (25 µm) compared to the control solution in the CLSM study. The gel formulation's pH, drug concentration, and texture were assessed. This study developed QbD-optimized 6-gingerol-loaded transfersomes. 6-GTF gel improved skin absorption, drug release, and antioxidant activity. These results show that the 6-GTF gel formulation has the ability to treat pain-related illnesses effectively. Hence, this study offers a possible topical treatment for conditions connected to pain.

Preclinical Assessment of ADAM9-Responsive Mesoporous Silica Nanoparticles for the Treatment of Pancreatic Cancer.

Pancreatic adenocarcinoma (PDAC) remains largely refractory to chemotherapeutic treatment regimens and, consequently, has the worst survival rate of all cancers. The low efficacy of current treatments results largely from toxicity-dependent dose limitations and premature cessation of therapy. Recently, targeted delivery approaches that may reduce off-target toxicities have been developed. In this paper, we present a preclinical evaluation of a PDAC-specific drug delivery system based on mesoporous silica nanoparticles (MSNs) functionalized with a protease linker that is specifically cleaved by PDAC cells. Our previous work demonstrated that ADAM9 is a PDAC-enriched protease and that paclitaxel-loaded ADAM9-responsive MSNs effectively kill PDAC cells in vitro. Here, we show that paclitaxel-loaded ADAM9-MSNs result in off-target cytotoxicity in clinically relevant models, which spurred the development of optimized ADAM9-responsive MSNs (OPT-MSNs). We found that these OPT-MSNs still efficiently kill PDAC cells but, as opposed to free paclitaxel, do not induce death in neuronal or bone marrow cells. In line with these in vitro data, paclitaxel-loaded OPT-MSNs showed reduced organ damage and leukopenia in a preclinical PDAC xenograft model. However, no antitumor response was observed upon OPT-MSN administration in vivo. The poor in vivo antitumor activity of OPT-MSNs despite efficient antitumor effects in vitro highlights that although MSN-based tumor-targeting strategies may hold therapeutic potential, clinical translation does not seem as straightforward as anticipated.

Implantable sustained-release drug delivery systems: a revolution for ocular therapeutics.

PURPOSE: Due to the inimitable anatomical structure of the eyeball and various physiological barriers, conventional ocular local administration is often complicated by apparent shortcomings, such as limited bioavailability and short drug retention. Thus, developing methods for sustainable, safe and efficient drug delivery to ocular target sites has long been an urgent need. This study briefly summarizes the barriers to ocular drug administration and various ocular drug delivery routes and highlights recent progress in ocular implantable sustained-release drug delivery systems (DDSs) to provide literature evidence for developing novel ocular implants for sustained drug delivery. METHODS: We conducted a comprehensive search of studies on ocular implantable sustained-release DDSs in PubMed and Web of Science using the following keywords: ocular, implantable and drug delivery system. More than 400 papers were extracted. Publications focused on sustained and controlled drug release were primarily considered. Experimental articles involving DDSs that cannot be implanted into the eye through surgeries and cannot be inserted into ocular tissues in solid form were excluded. Approximately 143 publications were reviewed to summarize the most current information on the subject. RESULTS: In recent years, numerous ocular sustained-release DDSs using lipids, nanoparticles and hydrogels as carriers have emerged. With unique properties and systematic design, ocular implantable sustained-release DDSs are able to continuously maintain drug release, effectively sustain the therapeutic concentration in target tissues, and substantially enhance the therapeutic efficacy. Nevertheless, few ocular implantable sustained-release DDSs have been available in clinical use. CONCLUSIONS: Ocular implantable sustained-release DDSs have become a new focus in the field of ocular drug development through unique designs and improvements in the materials of drug carriers, administration methods and dosage forms. With more ocular implantable sustained-release DDSs being commercialized, ocular therapeutics may be revolutionized.

Liposomes trigger bone marrow niche macrophage "foam" cell formation and affect hematopoiesis in mice.

Liposomes are the most widely used nanocarrier platform for the delivery of therapeutic and diagnostic agents, and a number of liposomes have been approved for use in clinical practice. After systemic administration, most liposomes are cleared by macrophages in the mononuclear phagocyte system, such as the liver and bone marrow (BM). However, the majority of studies have focused on investigating the therapeutic results of liposomal drugs, and too few studies have evaluated the potential side effects of empty nanocarriers on the functions of macrophages in the mononuclear phagocyte system. Here, we evaluate the potential effects of empty liposomes on the functions of BM niche macrophages. Following liposome administration, we observed lipid droplet (LD) accumulation in cultured primary macrophages and BM niche macrophages. We found that these LD-accumulating macrophages, similar to foam cells, exhibited increased expression of inflammatory cytokines, such as IL-1ß and IL-6. We further provided evidence that liposome deposition and degradation induced LD biogenesis on the endoplasmic reticulum membrane and subsequently disturbed endoplasmic reticulum homeostasis and activated the inositol-requiring transmembrane kinase/endoribonuclease 1α/NF-κB signaling pathway, which is responsible for the inflammatory activation of macrophages after liposome engulfment. Finally, we also showed the side effects of dysfunctional BM niche macrophages on hematopoiesis in mice, such as the promotion of myeloid-biased output and impairment of erythropoiesis. This study not only draws attention to the safety of liposomal drugs in clinical practice but also provides new directions for the design of lipid-based drug carriers in preclinical studies.

Paclitaxel-based supramolecular hydrogel loaded with mifepristone for the inhibition of breast cancer metastasis.

Breast cancer is the leading cause of cancer death among women and almost all of the breast cancer-caused mortality is related to metastasis. It has been reported that glucocorticoid facilitates the metastasis of breast cancer in mice, and mifepristone can antagonize the effect of glucocorticoid. Paclitaxel is one of the important drugs in the treatment of breast cancer. Mifepristone combined with paclitaxel could be an effective strategy for inhibiting breast cancer metastasis. However, their inherent defects, in terms of short blood circulation half-life and lack of tumor targeting, not only limit their effectiveness but also cause adverse reactions. Therefore, our aim is to explore a novel protocol against breast cancer metastasis, further optimize its therapeutic efficacy by a nanodelivery system, and explore its mechanism. Herein, a paclitaxel-conjugated and mifepristone-loaded hydrogel (PM-nano) was prepared by self-assembly. Its characterizations were studied. The antimetastatic effect was evaluated in vitro and in vivo and its mechanism was also explored by western blot assay. The resultant PM-nano was developed with favorable water solubility and good biocompatibility. Moreover, PM-nano displayed increased cell uptake properties and stimulated drug release in the tumor micro-acidic environment. The PM-nano was more effective in inhibiting the proliferation and metastasis of breast cancer than other groups in vitro and in vivo. The PM-nano might inhibit metastasis through glucocorticoid receptor/receptor tyrosine kinase-like orphan receptor 1 and MMPs. Taken together, PM-nano showed superior antimetastatic effects against breast cancer and excellent biocompatibility in vitro and in vivo, providing a new option for limiting metastasis.

Micro-Nanocarriers Based Drug Delivery Technology for Blood-Brain Barrier Crossing and Brain Tumor Targeting Therapy.

The greatest obstacle to using drugs to treat brain tumors is the blood-brain barrier (BBB), making it difficult for conventional drug molecules to enter the brain. Therefore, how to safely and effectively penetrate the BBB to achieve targeted drug delivery to brain tumors has been a challenging research problem. With the intensive research in micro- and nanotechnology in recent years, nano drug-targeted delivery technologies have shown great potential to overcome this challenge, such as inorganic nanocarriers, organic polymer-carriers, liposomes, and biobased carriers, which can be designed in different sizes, shapes, and surface functional groups to enhance their ability to penetrate the BBB and targeted drug delivery for brain tumors. In this review, the composition and overcoming patterns of the BBB are detailed, and then the hot research topics of drug delivery carriers for brain tumors in recent years are summarized, and their mechanisms of action on the BBB and the factors affecting drug delivery are described in detail, and the effectiveness of targeted therapy for brain tumors is evaluated. Finally, the challenges and dilemmas in developing brain tumor drug delivery systems are discussed, which will be promising in the future for targeted drug delivery to brain tumors based on micro-nanocarriers technology.

Red-Light-Responsive Metallopolymer Nanocarriers with Conjugated and Encapsulated Drugs for Phototherapy Against Multidrug-Resistant Tumors.

It is challenging to treat multidrug-resistant tumors because such tumors are resistant to a broad spectrum of structurally and functionally unrelated drugs. Herein, treatment of multidrug-resistant tumors using red-light-responsive metallopolymer nanocarriers that are conjugated with the anticancer drug chlorambucil (CHL) and encapsulated with the anticancer drug doxorubicin (DOX) is reported. An amphiphilic metallopolymer PolyRuCHL that contains a poly(ethylene glycol) (PEG) block and a red-light-responsive ruthenium (Ru)-containing block is synthesized. Chlorambucil is covalently conjugated to the Ru moieties of PolyRuCHL. Encapsulation of DOX into PolyRuCHL in an aqueous solution results in DOX@PolyRuCHL micelles. The DOX@PolyRuCHL micelles are efficiently taken up by the multidrug-resistant breast cancer cell line MCF-7R and which carries DOX into the cells. Free DOX, without the nanocarriers, is not taken up by MCF-7R or pumped out of MCF-7R via P-glycoproteins. Red light irradiation of DOX@PolyRuCHL micelles triggers the release of chlorambucil-conjugated Ru moieties and DOX. Both act synergistically to inhibit the growth of multidrug-resistant cancer cells. Furthermore, the inhibition of the growth of multidrug-resistant tumors in a mouse model using DOX@PolyRuCHL micelles is demonstrated. The design of red-light-responsive metallopolymer nanocarriers with both conjugated and encapsulated drugs opens up an avenue for photoactivated chemotherapy against multidrug-resistant tumors.

Polyester Dendrimers Based on Bis-MPA for Doxorubicin Delivery.

Although doxorubicin (DOX) is one of the most used chemotherapeutic drugs due to its efficacy against a wide group of cancer types, it presents severe side effects. As such, intensive research is being carried out to find new nanoscale systems that can help to overcome this problem. Polyester dendrimers based on the monomer 2,2-bis(hydroxymethyl)propionic acid (bis-MPA) are very promising systems for biomedical applications due to their biodegradability properties. In this study, bis-MPA-based dendrimers were, for the first time, evaluated as DOX delivery vehicles. Generations 4 and 5 of bis-MPA-based dendrimers with hydroxyl groups at the surface were used (B-G4-OH and B-G5-OH), together with dendrimers partially functionalized with amine groups (B-G4-NH2/OH and B-G5-NH2/OH). Partial functionalization was chosen because the main purpose was to compare the effect of different functional groups on dendrimers' drug delivery behavior without compromising cell viability, which is often affected by dendrimers' cationic charge. Results revealed that bis-MPA-based dendrimers were cytocompatible, independently of the chemical groups that were present at their surface. The B-G4-NH2/OH and B-G5-NH2/OH dendrimers were able to retain a higher number of DOX molecules, but the in vitro release of the drug was faster. On the contrary, the hydroxyl-terminated dendrimers exhibited a lower loading capacity but were able to deliver the drug in a more sustained manner. These results were in accordance with the cytotoxicity studies performed in several models of cancer cell lines and human mesenchymal stem cells. Overall, the results confirmed that it is possible to tune the drug delivery properties of bis-MPA-based dendrimers by modifying surface functionalization. Moreover, molecular modeling studies provided insights into the nature of the interactions established between the drug and the bis-MPA-based dendrimers─DOX molecules attach to their surface rather than being physically encapsulated.