Development and Characterization of Olaparib-Loaded Solid Self-Nanoemulsifying Drug Delivery System (S-SNEDDS) for Pharmaceutical Applications.

This study aims to enhance the solubility of Olaparib, classified as biopharmaceutical classification system (BCS) class IV due to its low solubility and bioavailability using a solid self-nanoemulsifying drug delivery system (S-SNEDDS). For this purpose, SNEDDS formulations were created using Capmul MCM as the oil, Tween 80 as the surfactant, and PEG 400 as the co-surfactant. The SNEDDS formulation containing olaparib (OLS-352), selected as the optimal formulation, showed a mean droplet size of 87.0 ± 0.4 nm and drug content of 5.53 ± 0.09%. OLS-352 also demonstrated anticancer activity against commonly studied ovarian (SK-OV-3) and breast (MCF-7) cancer cell lines. Aerosil® 200 and polyvinylpyrrolidone (PVP) K30 were selected as solid carriers, and S-SNEDDS formulations were prepared using the spray drying method. The drug concentration in S-SNEDDS showed no significant changes (98.4 ± 0.30%, 25℃) with temperature fluctuations during the 4-week period, demonstrating improved storage stability compared to liquid SNEDDS (L-SNEDDS). Dissolution tests under simulated gastric and intestinal conditions revealed enhanced drug release profiles compared to those of the raw drug. Additionally, the S-SNEDDS formulation showed a fourfold greater absorption in the Caco-2 assay than the raw drug, suggesting that S-SNEDDS could improve the oral bioavailability of poorly soluble drugs like olaparib, thus enhancing therapeutic outcomes. Furthermore, this study holds significance in crafting a potent and cost-effective pharmaceutical formulation tailored for the oral delivery of poorly soluble drugs.

Development of a sorafenib-loaded solid self-nanoemulsifying drug delivery system: Formulation optimization and characterization of enhanced properties.

Sorafenib, marketed under the brand name Nexavar®, is a multiple tyrosine kinase inhibitor drug that has been actively used in the clinical setting for the treatment of several cancers. However, the low solubility and bioavailability of sorafenib constitute a significant barrier to achieving a good therapeutic outcome. We developed a sorafenib-loaded self-nanoemulsifying drug delivery system (SNEDDS) formulation composed of capmul MCM, tween 80, and tetraglycol, and demonstrated that the SNEDDS formulation could improve drug solubility with excellent self-emulsification ability. Moreover, the sorafenib-loaded SNEDDS exhibited anticancer activity against Hep3B and KB cells, which are the most commonly used hepatocellular carcinoma and oral cancer cell lines, respectively. Subsequently, to improve the storage stability and to increase the possibility of commercialization, a solid SNEDDS for sorafenib was further developed through the spray drying method using Aerosil® 200 and PVP K 30. X-ray diffraction and differential scanning calorimeter data showed that the crystallinity of the drug was markedly reduced, and the dissolution rate of the drug was further improved in formulation in simulated gastric and intestinal fluid conditions. In vivo study, the bioavailability of the orally administered formulation increases dramatically compared to the free drug. Our results highlight the use of the solid-SNEDDS formulation to enhance sorafenib's bioavailability and outlines potential translational directions for oral drug development.

Drug-Dependent Morphological Transitions in Spherical and Worm-Like Polymeric Micelles Define Stability and Pharmacological Performance of Micellar Drugs.

Significant advances in physicochemical properties of polymeric micelles enable optimization of therapeutic drug efficacy, supporting nanomedicine manufacturing and clinical translation. Yet, the effect of micelle morphology on pharmacological efficacy is not adequately addressed. This work addresses this gap by assessing pharmacological efficacy of polymeric micelles with spherical and worm-like morphologies. It is observed that poly(2-oxazoline)-based polymeric micelles can be elongated over time from a spherical structure to worm-like structure, with elongation influenced by several conditions, including the amount and type of drug loaded into the micelles. The role of different morphologies on pharmacological performance of drug loaded micelles against triple-negative breast cancer and pancreatic cancer tumor models is further evaluated. Spherical micelles accumulate rapidly in the tumor tissue while retaining large amounts of drug; worm-like micelles accumulate more slowly and only upon releasing significant amounts of drug. These findings suggest that the dynamic character of the drug-micelle structure and the micelle morphology play a critical role in pharmacological performance, and that spherical micelles are better suited for systemic delivery of anticancer drugs to tumors when drugs are loosely associated with the polymeric micelles.

The DPA-derivative 11S, 17S-dihydroxy 7,9,13,15,19 (Z,E,Z,E,Z)-docosapentaenoic acid inhibits IL-6 production by inhibiting ROS production and ERK/NF-κB pathway in keratinocytes HaCaT stimulated with a fine dust PM10.

11 S, 17S-dihydroxy 7,9,13,15,19 (Z,E,Z,E,Z)-docosapentaenoic acid (DoPE) is a derivative of docosapentaenoic acid, a specialized pro-resolving mediator of inflammation such as lipoxins, resolvins, maresins, and protectins. PM10 is a fine dust particle that induces oxidative stress, DNA damage, inflammation, aging, and cancer. The anti-inflammatory mechanism of DoPE, however, has not yet been elucidated. In these studies, we investigated whether DoPE has anti-inflammatory effects in human keratinocyte HaCaT cells. We demonstrated that DoPE suppressed PM10-induced expressions of IL-6 mRNA and protein in human HaCaT keratinocytes. We also investigated the modulating effects of DoPE on reactive oxygen species (ROS) and mitogen-activated protein kinase (MAPK). ROS production, extracellular signal regulated kinase (ERK) phosphorylation, and translocation of nuclear factor-kappa B (NF-kB) p65 and NF-kB activity were suppressed by DoPE in PM10-stimulated HaCaT cells. Collectively, our results demonstrated that DoPE inhibited IL-6 expression by reducing ROS generation, suppressing ERK phosphorylation, and inhibiting translocation of NF-kB p65 and NF-kB activity in PM10-stimulated HaCaT cells, suggesting that DoPE can be useful for the resolution of the inflammation caused by IL-6.

Poly(2-oxazoline) nanoparticle delivery enhances the therapeutic potential of vismodegib for medulloblastoma by improving CNS pharmacokinetics and reducing systemic toxicity.

We report a nanoparticle formulation of the SHH-pathway inhibitor vismodegib that improves efficacy for medulloblastoma, while reducing toxicity. Limited blood-brain barrier (BBB) penetration and dose-limiting extitle/citraneural toxicities complicate systemic therapies for brain tumors. Vismodegib is FDA-approved for SHH-driven basal cell carcinoma, but implementation for medulloblastoma has been limited by inadequate efficacy and excessive bone toxicity. To address these issues through optimized drug delivery, we formulated vismodegib in polyoxazoline block copolymer micelles (POx-vismo). We then evaluated POx-vismo in transgenic mice that develop SHH-driven medulloblastomas with native vasculature and tumor microenvironment. POx-vismo improved CNS pharmacokinetics and reduced bone toxicity. Mechanistically, the nanoparticle carrier did not enter the CNS, and acted within the vascular compartment to improve drug delivery. Unlike conventional vismodegib, POx-vismo extended survival in medulloblastoma-bearing mice. Our results show the broad potential for non-targeted nanoparticle formulation to improve systemic brain tumor therapy, and specifically to improve vismodegib therapy for SHH-driven cancers.

Preparation and Characterization of a Lutein Solid Dispersion to Improve Its Solubility and Stability.

Lutein has been used as a dietary supplement for the treatment of eye diseases, especially age-related macular degeneration. For oral formulations, we investigated lutein stability in artificial set-ups mimicking different physiological conditions and found that lutein was degraded over time under acidic conditions. To enhance the stability of lutein upon oral intake, we developed enteric-coated lutein solid dispersions (SD) by applying a polymer, hydroxypropyl methylcellulose acetate succinate (HPMCAS-LF), through a solvent-controlled precipitation method. The SD were characterized in crystallinity, morphology, and drug entrapment. In the dissolution profile of lutein SD, a F80 formulation showed resistance toward the acidic environment under simulated gastric conditions while exhibiting a bursting drug release under simulated intestinal conditions. Our results highlight the potential use of HPMCAS-LF as an effective matrix to enhance lutein bioavailability during oral delivery and to provide novel insights into the eye-care supplement industry, with direct benefits for the health of patients.

A threonine turnstile defines a dynamic amphiphilic binding motif in the AAA ATPase p97 allosteric binding site.

The turnstile motion of two neighboring threonines sets up a dynamic side chain interplay that can accommodate both polar and apolar ligands in a small molecule allosteric protein binding site. A computational model based on SAR data and both X-ray and cryo-EM structures of the AAA ATPase p97 was used to analyze the effects of paired threonines at the inhibitor site. Specifically, the Thr side chain hydroxyl groups form a hydrogen bonding network that readily accommodates small, highly polar ligand substituents. Conversely, diametric rotation of the χ1 torsion by 150-180° orients the side chain ß-methyl groups into the binding cleft, creating a hydrophobic pocket that can accommodate small, apolar substituents. This motif was found to be critical for rationalizing the affinities of a structurally focused set of inhibitors of p97 covering a > 2000-fold variation in potencies, with a preference for either small-highly polar or small-apolar groups. The threonine turnstile motif was further validated by a PDB search that identified analogous binding modes in ligand interactions in PKB, as well as by an analysis of NMR structures demonstrating additional gear-like interactions between adjacent Thr pairs. Combined, these data suggest that the threonine turnstile motif may be a general feature of interest in protein binding pockets.

Mitochondrial targeted ß-lapachone induces mitochondrial dysfunction and catastrophic vacuolization in cancer cells.

Mitochondria play important roles in tumor cell physiology and survival by providing energy and metabolites for proliferation and metastasis. As part of their oncogenic status, cancer cells frequently produce increased levels of mitochondrial-generated reactive oxygen species (ROS). However, extensive stimulation of ROS generation in mitochondria has been shown to be able to induce cancer cell death, and is one of the major mechanisms of action of many anticancer agents. We hypothesized that enhancing mitochondrial ROS generation through direct targeting of a ROS generator into mitochondria will exhibit tumor cell selectivity, as well as high efficacy in inducing cancer cell death. We thus synthesized a mitochondrial targeted version of ß-lapachone (XJB-Lapachone) based on our XJB mitochondrial targeting platform. We found that the mitochondrial targeted ß-lapachone is more efficient in inducing apoptosis compared to unconjugated ß-lapachone, and the tumor cell selectivity is maintained. XJB-Lapachone also induced extensive cellular vacuolization and autophagy at a concentration not observed with unconjugated ß-lapachone. Through characterization of mitochondrial function we revealed that XJB-Lapachone is indeed more capable of stimulating ROS generation in mitochondria, which led to a dramatic mitochondrial uncoupling and autophagic degradation of mitochondria. Taken together, we have demonstrated that targeting ß-lapachone accomplishes higher efficacy through inducing ROS generation directly in mitochondria, resulting in extensive mitochondrial and cellular damage. XJB-Lapachone will thus help to establish a novel platform for the design of next generation mitochondrial targeted ROS generators for cancer therapy.

A practical handbook on single-cell RNA sequencing data quality control and downstream analysis.

Advancements in single-cell analysis have facilitated high-resolution observation of the transcriptome in individual cells. However, standards for obtaining high-quality cells and data analysis pipelines remain variable. Here, we provide the groundwork for improving the quality of single-cell analysis by delineating guidelines for selecting high-quality cells and considerations throughout the analysis. This review will streamline researchers' access to single-cell analysis and serve as a valuable guide for analysis.

Recent Advances in Intranasal Administration for Brain-Targeting Delivery: A Comprehensive Review of Lipid-Based Nanoparticles and Stimuli-Responsive Gel Formulations.

Addressing disorders related to the central nervous system (CNS) remains a complex challenge because of the presence of the blood-brain barrier (BBB), which restricts the entry of external substances into the brain tissue. Consequently, finding ways to overcome the limited therapeutic effect imposed by the BBB has become a central goal in advancing delivery systems targeted to the brain. In this context, the intranasal route has emerged as a promising solution for delivering treatments directly from the nose to the brain through the olfactory and trigeminal nerve pathways and thus, bypassing the BBB. The use of lipid-based nanoparticles, including nano/microemulsions, liposomes, solid lipid nanoparticles, and nanostructured lipid carriers, has shown promise in enhancing the efficiency of nose-to-brain delivery. These nanoparticles facilitate drug absorption from the nasal membrane. Additionally, the in situ gel (ISG) system has gained attention owing to its ability to extend the retention time of administered formulations within the nasal cavity. When combined with lipid-based nanoparticles, the ISG system creates a synergistic effect, further enhancing the overall effectiveness of brain-targeted delivery strategies. This comprehensive review provides a thorough investigation of intranasal administration. It delves into the strengths and limitations of this specific delivery route by considering the anatomical complexities and influential factors that play a role during dosing. Furthermore, this study introduces strategic approaches for incorporating nanoparticles and ISG delivery within the framework of intranasal applications. Finally, the review provides recent information on approved products and the clinical trial status of products related to intranasal administration, along with the inclusion of quality-by-design-related insights.

Establishment and Characterization of Immortalized Human Dermal Papilla Cells Expressing Human Papillomavirus 16 E6/E7.

Primary human dermal papilla cells (HDPCs) are often preferred in studies on hair growth and regeneration. However, primary HDPCs are limited by their reduced proliferative capacity, decreased hair induction potential, and extended doubling times at higher passages. To overcome these limitations, pTARGET vectors containing human papillomavirus16 (HPV16) E6/E7 oncogenes were transfected into HDPCs and selected using G-148 to generate immortalized cells here. HPV16 E6/E7 oncogenes were efficiently transfected into primary HDPCs. Immortalized HDPC showed higher proliferative activity than primary HDPC, confirming an increased proliferation rate. Expression of p53 and pRb proteins was downregulated by E6 and E7, respectively. E6/E7 expressing HDPC cells revealed that cyclin-dependent kinase (CDK) inhibitor p21 expression was decreased, while cell cycle-related genes and proteins (CDK2 and cyclin E) and E2F family genes were upregulated. Immortalized HDPCs maintained their responsiveness to Wnt/ß-catenin pathway and hair follicle formation capability, as indicated by their aggregative properties and stemness. E6/E7 immortalized HDPCs may facilitate in vitro hair growth and regeneration studies.

Tumor microenvironment immunomodulation by nanoformulated TLR 7/8 agonist and PI3k delta inhibitor enhances therapeutic benefits of radiotherapy.

Infiltration of immunosuppressive cells into the breast tumor microenvironment (TME) is associated with suppressed effector T cell (Teff) responses, accelerated tumor growth, and poor clinical outcomes. Previous studies from our group and others identified infiltration of immunosuppressive myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) as critical contributors to immune dysfunction in the orthotopic triple-negative breast cancer (TNBC) tumor model limiting the efficacy of adoptive cellular therapy. However, approaches to target these cells specifically in the TME are currently lacking. To overcome this barrier, polymeric micelles nanoparticles (PMNPs) were used for co-delivery of small molecule drugs activating Toll-like receptors 7 and 8 (TLR7/8) and inhibiting PI3K delta. The immunomodulation of the TME by TLR7/8 agonist and PI3K inhibitor altered macrophage polarization, reduced MDSC accumulation and selectively decreased tissue-resident Tregs in the TME, while enhancing the T and B cell adaptive immune response. PMNPs significantly enhanced the anti-tumor activity of local radiation therapy (RT) in mice bearing orthotopic TNBC tumors compared to RT alone. Taken together, these data demonstrate that RT combined with a nanoformulated immunostimulant restructured the TME and has promising potential for future translation combined with RT for patients with TNBC.

Specialized pro-resolving mediator 7S MaR1 inhibits IL-6 expression via modulating ROS/p38/ERK/NF-κB pathways in PM10-exposed keratinocytes.

Keratinocytes are susceptible to airborne particulate matter (PM) exposure, resulting in human skin barrier dysfunction. Therefore, it is important to find useful reagents to resolve skin damages caused by PM. Here, we explored the protective effect of 7S MaR1, a specialized pro-resolving mediator derived from docosahexaenoic acid, on skin inflammation and the oxidative stress induced by PM with a diameter 10 µm or less (PM10) in human keratinocyte HaCaT cells. Interestingly, PM10-induced ROS generation was modulated by 7S MaR1 via the recovery of ROS scavenger genes. 7S MaR1 reduced PM10-induced IL-6 expression via modulating the p38/ERK/NF-κB signaling pathways. These results demonstrate that PM10 induces inflammatory cytokines, which can lead to skin diseases. In addition, 7S MaR1 can resolve inflammation caused by PM10-induced oxidative stress and inflammatory cytokines.

Synthesis and biological evaluation of a polyyne-containing sphingoid base probe as a chemical tool.

The sphingolipid metabolites have emerged as a starting point for the development of novel therapeutics for many diseases. However, details of the functions and mechanisms of sphingolipids remain unknown. To better understand the roles of sphingolipids, chemical tools with unique biological and physicochemical properties are needed. In this regard, we previously reported the synthesis of sphingoid base analogues in which the carbon chains are restricted by triple bonds. Here, we have conjugated a fluorescent dye to the polyyne analogues of the sphingoid bases to generate optical probes. Like the parent polyyne-containing sphingoid base, the 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD)-labeled triyne-sphingosine inhibited cancer cell growth far more effectively than did the corresponding sphingosine. NBD-triyne-sphingosine was rapidly incorporated into the cells and displayed broad cytoplasmic distribution. According to the results of a flow cytometric analysis, cancer cells fed with NBD-triyne-sphingosine showed significantly increased fluorescence intensity compared with the NBD-sphingosine treated cells. The metabolism of NBD-triyne-sphingosine was somewhat different from that of NBD-sphingosine. These results indicated that the incorporated rigid polyyne moiety in the sphingoid base altered the physicochemical properties of the sphingolipid, thereby affecting its biological behavior. The higher antiproliferative activity in the SRB assay and the significantly higher fluorescence intensity observed in the flow cytometric analysis are some of the interesting and distinct aspects of NBD-triyne-sphingosine compared to standard NBD-sphingosine probes. Thus, it is believed that the fluorescently labeled polyyne-containing sphingoid base developed in this study will be a useful chemical tool in sphingolipid research.

Tumor microenvironment stimuli-responsive lipid-drug conjugates for cancer treatment.

Lipid drug conjugates (LDCs) have attracted considerable attention in the fields of drug delivery and pharmacology due to their ability to target specific cells, increase drug solubility, reduce toxicity, and improve therapeutic efficacy. These unique features make LDCs promising candidates for the treatment cancer, inflammation, and infectious diseases. In fact, by choosing specific linkers between the lipid and drug molecules, stimuli-responsive LDCs can be designed to target cancer cells based on the unique properties of the tumor microenvironment. Despite the fact that many reviews have described LDCs, few articles have focused on tumor microenvironmental stimuli-responsive LDCs for cancer treatment. Therefore, the key elements of these types of LDCs in cancer treatment will be outlined and discussed in this paper. Our paper goes into detail on the concepts and benefits of LDCs, the various types of tumor microenvironment stimuli-responsive LDCs (such as pH, redox, enzyme, or reactive oxygen species-responsive LDCs), and the current status of LDCs in clinical trials.

Human IL-32θA94V mutant attenuates monocyte-endothelial adhesion by suppressing the expression of ICAM-1 and VCAM-1 via binding to cell surface receptor integrin αVß3 and αVß6 in TNF-α-stimulated HUVECs.

Interleukin-32 (IL-32), first reported in 2005, and its isoforms have been the subject of numerous studies investigating their functions in virus infection, cancer, and inflammation. IL-32θ, one of the IL-32 isoforms, has been shown to modulate cancer development and inflammatory responses. A recent study identified an IL-32θ mutant with a cytosine to thymine replacement at position 281 in breast cancer tissues. It means that alanine was also replaced to valine at position 94 in amino acid sequence (A94V). In this study, we investigated the cell surface receptors of IL-32θA94V and evaluated their effect on human umbilical vein endothelial cells (HUVECs). Recombinant human IL-32θA94V was expressed, isolated, and purified using Ni-NTA and IL-32 mAb (KU32-52)-coupled agarose columns. We observed that IL-32θA94V could bind to the integrins αVß3 and αVß6, suggesting that integrins act as cell surface receptors for IL-32θA94V. IL-32θA94V significantly attenuated monocyte-endothelial adhesion by inhibiting the expression of Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in tumor necrosis factor (TNF)-α-stimulated HUVECs. IL-32θA94V also reduced the TNF-α-induced phosphorylation of protein kinase B (AKT) and c-jun N-terminal kinases (JNK) by inhibiting phosphorylation of focal adhesion kinase (FAK). Additionally, IL-32θA94V regulated the nuclear translocation of nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1), which are involved in ICAM-1 and VCAM-1 expression. Monocyte-endothelial adhesion mediated by ICAM-1 and VCAM-1 is an important early step in atherosclerosis, which is a major cause of cardiovascular disease. Our findings suggest that IL-32θA94V binds to the cell surface receptors, integrins αVß3 and αVß6, and attenuates monocyte-endothelial adhesion by suppressing the expression of ICAM-1 and VCAM-1 in TNF-α-stimulated HUVECs. These results demonstrate that IL-32θA94V can act as an anti-inflammatory cytokine in a chronic inflammatory disease such as atherosclerosis.

Effects of PEG-Linker Chain Length of Folate-Linked Liposomal Formulations on Targeting Ability and Antitumor Activity of Encapsulated Drug.

Introduction: Ligand-conjugated liposomes are promising for the treatment of specific receptor-overexpressing cancers. However, previous studies have shown inconsistent results because of the varying properties of the ligand, presence of a polyethylene glycol (PEG) coating on the liposome, length of the linker, and density of the ligand. Methods: Here, we prepared PEGylated liposomes using PEG-linkers of various lengths conjugated with folate and evaluated the effect of the PEG-linker length on the nanoparticle distribution and pharmacological efficacy of the encapsulated drug both in vitro and in vivo. Results: When folate was conjugated to the liposome surface, the cellular uptake efficiency in folate receptor overexpressed KB cells dramatically increased compared to that of the normal liposome. However, when comparing the effect of the PEG-linker length in vitro, no significant difference between the formulations was observed. In contrast, the level of tumor accumulation of particles in vivo significantly increased when the length of the PEG-linker was increased. The tumor size was reduced by >40% in the Dox/FL-10K-treated group compared to that in the Dox/FL-2K- or 5K-treated groups. Discussion: Our study suggests that as the length of PEG-linker increases, the tumor-targeting ability can be enhanced under in vivo conditions, which can lead to an increase in the antitumor activity of the encapsulated drug.

Unsaturated oxidated fatty acid 12(S)-HETE attenuates TNF-α expression in TNF-α/IFN-γ-stimulated human keratinocytes.

Chronic skin inflammatory diseases are associated with abnormal immune responses characterized by skin barrier dysfunction. Keratinocytes participate in immune homeostasis regulated by immune cells. Immune homeostasis dysfunction contributes to the pathogenesis of skin diseases mediated by pro-inflammatory cytokines and chemokines, such as tumor necrosis factor (TNF)-α, which are produced by activated keratinocytes. 12(S)-Hydroxy eicosatetraenoic acid [12(S)-HETE], an arachidonic acid metabolite, has anti-inflammatory properties. However, the role of 12(S)-HETE in chronic skin inflammatory diseases has not been elucidated yet. In this study, we investigated the effect of 12(S)-HETE on TNF-α/interferon (IFN)-γ-induced pro-inflammatory cytokine and chemokine expression. Our data showed that 12(S)-HETE modulates TNF-α mRNA and protein expression in TNF-α-/IFN-γ-treated human keratinocytes. Molecular docking analyses demonstrated that 12(S)-HETE bound to extracellular signal-regulated kinase (ERK)1/2, thus preventing ERK activation and downregulating phosphorylated ERK expression. We also demonstrated that 12(S)-HETE treatment inhibited IκB and ERK phosphorylation and nuclear factor (NF)-κB, p65/p50, and CCAAT/enhancerbindingproteinß (C/EBPß) translocation. Overall, our results showed that 12(S)-HETE attenuated TNF-α expression and secretion by inhibiting the mitogen-activated protein kinase ERK/NF-κB and C/EBPß signaling pathways. Overall, these results suggest that 12(S)-HETE effectively resolved TNF-α-induced inflammation.

Development and characterization of pH-responsive nanocarriers for chemo-photothermal combination therapy of acidic tumors.

The combination of photothermal therapy and chemotherapy has been considered a promising strategy for improving the excellent antitumor activities of these treatments. In this study, we developed a new simple type of pH-sensitive chemo-photothermal combination agent capable of repeated exposures to a near-infrared (NIR) laser and evaluated its anticancer efficacy in vitro and in vivo. Doxorubicin (Dox) and gold nanoclusters (GNCs) were successfully co-loaded into pH-sensitive nanoparticles (poly(ethylene glycol)-poly[(benzyl-l-aspartate)-co-(N-(3-aminopropyl)imidazole-L-aspartamide)] (PEG-PABI)), resulting in a particle size of approximately120 nm with a narrow size distribution. The dual drug-loaded nanoparticles (Dox/GNC-loaded PEG-PABI micelles (Dox/GNC-Ms)) showed consistent pH-sensitive properties and heat generation efficiency after repeated NIR laser exposure. In particular, GNC-M has improved photothermal stability while maintaining high photothermal conversion efficiency, addressing the shortcomings of previous gold nanoparticles. As the concentration of GNC-Ms, irradiation light exposure time, and light source intensity increased, the amount of heat generated and the anticancer effect increased. When Dox was encapsulated with GNCs (Dox/GNC-Ms), a faster drug release rate under acidic pH conditions and a strong synergistic effect against U87MG cells were observed. When the Dox/GNC-M system was extended to in vivo studies, it effectively increased the temperature of the tumor tissue under near-infrared irradiation and showed excellent anticancer efficacy. Therefore, the Dox/GNC-M system could be a simple but promising strategy for chemo-photothermal combination treatment capable of targeting acidic tumors.

High-Dose Paclitaxel and its Combination with CSF1R Inhibitor in Polymeric Micelles for Chemoimmunotherapy of Triple Negative Breast Cancer.

The presence of immunosuppressive immune cells in tumors is a significant barrier to the generation of therapeutic immune responses. Similarly, in vivo triple-negative breast cancer (TNBC) models often contain prevalent, immunosuppressive tumor-associated macrophages in the tumor microenvironment (TME), resulting in breast cancer initiation, invasion, and metastasis. Here, we test systemic chemoimmunotherapy using small-molecule agents, paclitaxel (PTX), and colony-stimulating factor 1 receptor (CSF1R) inhibitor, PLX3397, to enhance the adaptive T cell immunity against TNBCs in immunocompetent mouse TNBC models. We use high-capacity poly(2-oxazoline) (POx)-based polymeric micelles to greatly improve the solubility of insoluble PTX and PLX3397 and widen the therapeutic index of such drugs. The results demonstrate that high-dose PTX in POx, even as a single agent, exerts strong effects on TME and induces long-term immune memory. In addition, we demonstrate that the PTX and PLX3397 combination provides consistent therapeutic improvement across several TNBC models, resulting from the repolarization of the immunosuppressive TME and enhanced T cell immune response that suppress both the primary tumor growth and metastasis. Overall, the work emphasizes the benefit of drug reformulation and outlines potential translational path for both PTX and PTX with PLX3397 combination therapy using POx polymeric micelles for the treatment of TNBC.