Reconstituted high density lipoprotein (rHDL), a versatile drug delivery nanoplatform for tumor targeted therapy

Self-Signal-Triggered Drug Delivery System for Tumor Therapy Using Cancer Cell Membrane-Coated Biocompatible Mn3O4 Nanocomposites

In anti-cancer metastasis treatment, precise drug delivery to cancer cells remains a challenge. Innovative nanocomposites are developed to tackle these issues effectively. The approach involves the creation of manganese oxide (Mn3O4) nanoparticles (NPs) and their functionalization using trisodium citrate to yield functionalized Mn3O4 NPs (F-Mn3O4 NPs), with enhanced water solubility, stability, and biocompatibility. Subsequently, the chemotherapeutic drug doxorubicin (DOX) is encapsulated with Mn3O4 NPs, resulting in DOX/Mn3O4 NPs. To achieve cell-specific targeting, These NPs are coated with HeLa cell membranes (HCM), forming HCM/DOX/Mn3O4. For further refinement, a transferrin (Tf) receptor is integrated with cracked HCM to create Tf-HCM/DOX/Mn3O4 nanocomposites (NC) with specific cell membrane targeting capabilities. The resulting Tf-HCM/DOX/Mn3O4 NC exhibits excellent drug encapsulation efficiency (97.5%) and displays triggered drug release when exposed to NIR laser irradiation in the tumor's environment (pH 5.0 and 6.5). Furthermore, these nanocomposites show resistance to macrophage uptake and demonstrate homotypic cancer cell targeting specificity, even in the presence of other tumor cells. In vitro toxicity tests show that Tf-HCM/DOX/Mn3O4 NC achieves significant anticancer activity against HeLa and BT20 cancer cells, with percentages of 76.46% and 71.36%, respectively. These results indicate the potential of Tf-HCM/DOX/Mn3O4 NC as an effective nanoplatform for chemo-photothermal therapy.

Development of Recombinant High-Density Lipoprotein Platform with Innate Adipose Tissue-Targeting Abilities for Regional Fat Reduction

As an escalating public health issue, obesity and overweight conditions are predispositions to various diseases and are exacerbated by concurrent chronic inflammation. Nonetheless, extant antiobesity pharmaceuticals (quercetin, capsaicin, catecholamine, etc.) manifest constrained efficacy alongside systemic toxic effects. Effective therapeutic approaches that selectively target adipose tissue, thereby enhancing local energy expenditure, surmounting the limitations of prevailing antiobesity modalities are highly expected. In this context, we developed a temperature-sensitive hydrogel loaded with recombinant high-density lipoprotein (rHDL) to achieve targeted delivery of resveratrol, an adipose browning activator, to adipose tissue. rHDL exhibits self-regulation on fat cell metabolism and demonstrates natural targeting toward scavenger receptor class B type I (SR-BI), which is highly expressed by fat cells, thereby achieving a synergistic effect for the treatment of obesity. Additionally, the dispersion of rHDL@Res in temperature-sensitive hydrogels, coupled with the regulation of their degradation and drug release rate, facilitated sustainable drug release at local adipose tissues over an extended period. Following 24 days' treatment regimen, obese mice exhibited improved metabolic status, resulting in a reduction of 68.2% of their inguinal white adipose tissue (ingWAT). Specifically, rHDL@Res/gel facilitated the conversion of fatty acids to phospholipids (PA, PC), expediting fat mobilization, mitigating triglyceride accumulation, and therefore facilitating adipose tissue reduction. Furthermore, rHDL@Res/gel demonstrated efficacy in attenuating obesity-induced inflammation and fostering angiogenesis in ingWAT. Collectively, this engineered local fat reduction platform demonstrated heightened effectiveness and safety through simultaneously targeting adipocytes, promoting WAT browning, regulating lipid metabolism, and controlling inflammation, showing promise for adipose-targeted therapy.

A decreased level of high-density lipoprotein is a possible risk factor for type 2 diabetes mellitus: A review

Introduction

Type 2 diabetes mellitus (T2DM) is characterized primarily by dyslipidemia and hyperglycemia due to insulin resistance. High-density lipoprotein (HDL) play a significant role in preventing the incidence of dyslipidemia and its complications. HDL has different protective functions, such as reducing oxidation, vascular inflammation, and thrombosis; additionally, its anti-diabetic role is one of the most significant recent discoveries about HDL and some of its constituent lipoproteins.

Methods

This research reviews ongoing studies and preliminary investigations into the assessment of relation between decreased level of HDL and T2DM.

Results

The levels of HDL and its functions contribute to glucose hemostasis and the development of T2DM through four possible mechanisms, including insulin secretion by beta cells, peripheral insulin sensitivity, non-insulin-dependent glucose uptake, and adipose tissue metabolic activity. Additionally, the anti-oxidant properties of HDL protect beta cells from apoptosis caused by oxidative stress and inflammation induced by low-density lipoprotein, which facilitate insulin secretion.

Conclusion

Therefore, HDL and its compositions, especially Apo A-I, play an important role in regulating glucose metabolism, and decreased levels of HDL can be considered a risk factor for DM. Different factors, such as hypoalphalipoproteinemia that manifests as a consequence of genetic factors, such as Apo A-I deficiency, as well as secondary causes arising from lifestyle choices and underlying medical conditions that decrease the level of HDL, could be associated with DM. Moreover, intricate connections between HDL and diabetic complications extend beyond glucose metabolism to encompass complications like cardiovascular disease and kidney disease. Therefore, the exact interactions between HDL level and DM should be evaluated in future studies.

Gemcitabine-loaded synthetic high-density lipoprotein preferentially eradicates hepatic monocyte-derived macrophages in mouse liver with colorectal cancer metastases

Liver metastasis of colorectal cancer (CRC) is the critical cause of CRC-related death due to its unique immunosuppressive microenvironment. In this study we generated a gemcitabine-loaded synthetic high-density lipoprotein (G-sHDL) to reverse immunosuppression in livers with CRC metastases. After intravenous injection, sHDL targeted hepatic monocyte-derived alternatively activated macrophages (Mono-M2) in the livers of mice bearing both subcutaneous tumors and liver metastases. The G-sHDL preferentially eradicated Mono-M2 in the livers with CRC metastases, which consequently prevented Mono-M2-mediated killing of tumor antigen-specific CD8+ T cells in the livers and thus improved the densities of tumor antigen-specific CD8+ T cells in the blood, tumor-draining lymph nodes and subcutaneous tumors of the treated mice. While reversing the immunosuppressive microenvironment, G-sHDL also induced immunogenic cell death of cancer cells, promoted maturation of dendritic cells, and increased tumor infiltration and activity of CD8+ T cells. Collectively, G-sHDL inhibited the growth of both subcutaneous tumors and liver metastases, and prolonged the survival of animals, which could be further improved when used in conjunction with anti-PD-L1 antibody. This platform can be a generalizable platform to modulate immune microenvironment of diseased livers.

Biokinetics, radiopharmacokinetics and estimation of the absorbed dose in healthy organs due to Technetium-99m transported in the core and on the surface of reconstituted high-density lipoprotein nanoparticles

The development of rHDL-radionuclide theragnostic systems requires evaluation of the absorbed doses that would be produced in healthy tissues and organs at risk. Technetium-99m is the most widely used radionuclide for diagnostic imaging, therefore, the design of theragnostic reconstituted high density-lipoprotein (rHDL) nanosystems labeled with Technetium-99m offers multiple possibilities.

OBJECTIVE

To determine the biokinetics, radiopharmacokinetics and estimate the absorbed doses induced in healthy organs by Technetium-99m transported in the core and on the surface of rHDL.

METHODS

Biokinetic and radiopharmacokinetic models of rHDL/[99mTc]Tc-HYNIC-DA (Technetium-99m in the core) and [99mTc]Tc-HYNIC-rHDL (Technetium-99m on the surface) were calculated from their ex vivo biodistribution in healthy mice. Absorbed doses were estimated by the MIRD formalism using OLINDA/EXM and LMFIT softwares.

RESULTS

rHDL/[99mTc]Tc-HYNIC-DA and [99mTc]Tc-HYNIC-rHDL show instantaneous absorption in kidney, lung, heart and pancreas, with slower absorption in spleen. rHDL/[99mTc]Tc-HYNIC-DA is absorbed more slowly in the intestine, while [99mTc]Tc-HYNIC-rHDL is absorbed more slowly in the liver. The main target organ for rHDL/[99mTc]Tc-HYNIC-DA, which is hydrophobic in nature, is the liver, whereas the kidney is for the more hydrophilic [99mTc]Tc-HYNIC-rHDL. Assuming that 925 MBq (25 mCi) of Technetium-99m, carried in the core or on the surface of rHDL, are administered, the maximum tolerated doses for the organs of greatest accumulation are not exceeded.

CONCLUSION

Theragnostic systems based on 99mTc-labeled rHDL are safe from the dosimetric point of view. The dose estimates obtained can be used to adjust the 99mTc-activity to be administered in future clinical trials.

Mannose-Coated Reconstituted Lipoprotein Nanoparticles for the Targeting of Tumor-Associated Macrophages: Optimization, Characterization, and In Vitro Evaluation of Effectiveness

Reconstituted high-density lipoprotein nanoparticles (rHDL NPs) have been utilized as delivery vehicles to a variety of targets, including cancer cells. However, the modification of rHDL NPs for the targeting of the pro-tumoral tumor-associated macrophages (TAMs) remains largely unexplored. The presence of mannose on nanoparticles can facilitate the targeting of TAMs which highly express the mannose receptor at their surface. Here, we optimized and characterized mannose-coated rHDL NPs loaded with 5,6-dimethylxanthenone-4-acetic acid (DMXAA), an immunomodulatory drug. Lipids, recombinant apolipoprotein A-I, DMXAA, and different amounts of DSPE-PEG-mannose (DPM) were combined to assemble rHDL-DPM-DMXAA NPs. The introduction of DPM in the nanoparticle assembly altered the particle size, zeta potential, elution pattern, and DMXAA entrapment efficiency of the rHDL NPs. Collectively, the changes in physicochemical characteristics of rHDL NPs upon the addition of the mannose moiety DPM indicated that the rHDL-DPM-DMXAA NPs were successfully assembled. The rHDL-DPM-DMXAA NPs induced an immunostimulatory phenotype in macrophages pre-exposed to cancer cell-conditioned media. Furthermore, rHDL-DPM NPs delivered their payload more readily to macrophages than cancer cells. Considering the effects of the rHDL-DPM-DMXAA NPs on macrophages, the rHDL-DPM NPs have the potential to serve as a drug delivery platform for the selective targeting of TAMs.

Ganglioside GM3-Functionalized Reconstituted High-Density Lipoprotein (GM3-rHDL) as a Novel Nanocarrier Enhances Antiatherosclerotic Efficacy of Statins in apoE-/- C57BL/6 Mice

Previously, we found that exogenous ganglioside GM3 had an antiatherosclerotic efficacy and that its antiatherosclerotic efficacy could be enhanced by reconstituted high-density lipoprotein (rHDL). In this study, we hypothesized that GM3-functionalized rHDL (i.e., GM3-rHDL) as a nanocarrier can promote the efficacy of traditional antiatherosclerotic drugs (e.g., statins). To test this hypothesis, lovastatin (LT) was used as a representative of statins, and LT-loaded GM3-rHDL nanoparticle (LT-GM3-rHDL or LT@GM3-rHDL; a mean size of ~142 nm) and multiple controls (e.g., GM3-rHDL without LT, LT-loaded rHDL or LT-rHDL, and other nanoparticles) were prepared. By using two different microsphere-based methods, the presences of apolipoprotein A-I (apoA-I) and/or GM3 in nanoparticles and the apoA-I-mediated macrophage-targeting ability of apoA-I/rHDL-containing nanoparticles were verified in vitro. Moreover, LT-GM3-rHDL nanoparticle had a slowly sustained LT release in vitro and the strongest inhibitory effect on the foam cell formation of macrophages (a key event of atherogenesis). After single administration of rHDL-based nanoparticles, a higher LT concentration was detected shortly in the atherosclerotic plaques of apoE^-/- mice than non-rHDL-based nanoparticles, suggesting the in vivo plaque-targeting ability of apoA-I/rHDL-containing nanoparticles. Finally, among all nanoparticles LT-GM3-rHDL induced the largest decreases in the contents of blood lipids and in the areas of atherosclerotic plaques at various aortic locations in apoE^-/- mice fed a high-fat diet for 12 weeks, supporting that LT-GM3-rHDL has the best in vivo antiatherosclerotic efficacy among the tested nanoparticles. Our data imply that GM3-functionalized rHDL (i.e., GM3-rHDL) can be utilized as a novel nanocarrier to enhance the efficacy of traditional antiatherosclerotic drugs (e.g., statins).

Engineered rHDL Nanoparticles as a Suitable Platform for Theranostic Applications

Reconstituted high-density lipoproteins (rHDLs) can transport and specifically release drugs and imaging agents, mediated by the Scavenger Receptor Type B1 (SR-B1) present in a wide variety of tumor cells, providing convenient platforms for developing theranostic systems. Usually, phospholipids or Apo-A1 lipoproteins on the particle surfaces are the motifs used to conjugate molecules for the multifunctional purposes of the rHDL nanoparticles. Cholesterol has been less addressed as a region to bind molecules or functional groups to the rHDL surface. To maximize the efficacy and improve the radiolabeling of rHDL theranostic systems, we synthesized compounds with bifunctional agents covalently linked to cholesterol. This strategy means that the radionuclide was bound to the surface, while the therapeutic agent was encapsulated in the lipophilic core. In this research, HYNIC-S-(CH2)3-S-Cholesterol and DOTA-benzene-p-SC-NH-(CH2)2-NH-Cholesterol derivatives were synthesized to prepare nanoparticles (NPs) of HYNIC-rHDL and DOTA-rHDL, which can subsequently be linked to radionuclides for SPECT/PET imaging or targeted radiotherapy. HYNIC is used to complexing 99mTc and DOTA for labeling molecules with 111, 113mIn, 67, 68Ga, 177Lu, 161Tb, 225Ac, and 64Cu, among others. In vitro studies showed that the NPs of HYNIC-rHDL and DOTA-rHDL maintain specific recognition by SR-B1 and the ability to internalize and release, in the cytosol of cancer cells, the molecules carried in their core. The biodistribution in mice showed a similar behavior between rHDL (without surface modification) and HYNIC-rHDL, while DOTA-rHDL exhibited a different biodistribution pattern due to the significant reduction in the lipophilicity of the modified cholesterol molecule. Both systems demonstrated characteristics for the development of suitable theranostic platforms for personalized cancer treatment.

Application Perspectives of Nanomedicine in Cancer Treatment

Cancer is a disease that seriously threatens human health. Based on the improvement of traditional treatment methods and the development of new treatment modes, the pattern of cancer treatment is constantly being optimized. Nanomedicine plays an important role in these evolving tumor treatment modalities. In this article, we outline the applications of nanomedicine in three important tumor-related fields: chemotherapy, gene therapy, and immunotherapy. According to the current common problems, such as poor targeting of first-line chemotherapy drugs, easy destruction of nucleic acid drugs, and common immune-related adverse events in immunotherapy, we discuss how nanomedicine can be combined with these treatment modalities, provide typical examples, and summarize the advantages brought by the application of nanomedicine.

Combining nanotechnology with the multifunctional roles of neutrophils against cancer and inflammatory disease

Neutrophils, the most abundant leukocytes in humans, play a crucial role in acute inflammation during infection and tumorigenesis. Neutrophils are the major types of cells recruited to the inflammation sites induced by pathogens, exhibiting great homing ability towards inflammatory disorders and tumor sites. Therefore, a neutrophil-based drug delivery system (NDDS) has become a promising platform for anti-cancer and anti-inflammatory treatment. Recent decades have witnessed the huge progress of applying nanomaterials in drug delivery. Nanomaterials are regarded as innovative components to enrich the field of neutrophil-based therapies due to their unique physiochemical characteristics. In this review, the latest advancement of combining diverse nanomaterials with an NDDS for cancer and inflammatory disease treatment will be summarized. It is discussed how nanomaterials empower the therapeutic area of an NDDS and how an NDDS circumvents the limitations of nanomaterials. Moreover, based on the finding that neutrophils are closely involved in the progression of cancer and inflammatory diseases, emerging therapeutic strategies that target neutrophils will be outlined. Finally, as neutrophils were demonstrated to play a central role in the immunopathology of COVID-19, which causes necroinflammation that is responsible for the cytokine storm and sepsis during coronavirus infections, novel therapeutic approaches that anchor neutrophils against the pathological consequences related to COVID-19 will be highlighted as well.

Multifunctional inorganic nanomaterials for cancer photoimmunotherapy

Phototherapy and immunotherapy in combination is regarded as the ideal therapeutic modality to treat both primary and metastatic tumors. Immunotherapy uses different immunological approaches to stimulate the immune system to identify tumor cells for targeted elimination. Phototherapy destroys the primary tumors by light irradiation, which induces a series of immune responses through triggering immunogenic cancer cell death. Therefore, when integrating immunotherapy with phototherapy, a novel anti-cancer strategy called photoimmunotherapy (PIT) is emerging. This synergistic treatment modality can not only enhance the effectiveness of both therapies but also overcome their inherent limitations, opening a new era for the current anti-cancer therapy. Recently, the advancement of nanomaterials affords a platform for PIT. From all these nanomaterials, inorganic nanomaterials stand out as ideal mediators in PIT due to their unique physiochemical properties. Inorganic nanomaterials can not only serve as carriers to transport immunomodulatory agents in immunotherapy owing to their excellent drug-loading capacity but also function as photothermal agents or photosensitizers in phototherapy because of their great optical characteristics. In this review, the recent advances of multifunctional inorganic nanomaterial-mediated drug delivery and their contributions to cancer PIT will be highlighted.

Insights on functionalized carbon nanotubes for cancer theranostics

Despite the exciting breakthroughs in medical technology, cancer still accounts for one of the principle triggers of death and conventional therapeutic modalities often fail to attain an effective cure. Recently, nanobiotechnology has made huge advancement in cancer therapy with gigantic application potential because of their ability in achieving precise and controlled drug release, elevating drug solubility and reducing adverse effects. Carbon nanotubes (CNTs), one of the most promising carbon-related nanomaterials, have already achieved much success in biomedical field. Due to their excellent optical property, thermal and electronic conductivity, easy functionalization ability and high drug loading capacity, CNTs can be applied in a multifunctional way for cancer treatment and diagnosis. In this review, we will give an overview of the recent progress of CNT-based drug delivery systems in cancer theranostics, which emphasizes their targetability to intracellular components of tumor cells and extracellular elements in tumor microenvironment. Moreover, a detailed introduction on how CNTs penetrate inside the tumor cells to reach their sites of action and achieve the therapeutic effects, as well as their diagnostic applications will be highlighted.

Combination of Nanomaterials in Cell-Based Drug Delivery Systems for Cancer Treatment

Cell-based drug delivery systems have shown tremendous advantages in cancer treatment due to their distinctive properties. For instance, delivery of therapeutics using tumor-tropic cells like neutrophils, lymphocytes and mesenchymal stem cells can achieve specific tumor targeting due to the "Trojan Horse" effect. Other circulatory cells like erythrocytes and platelets can greatly improve the circulation time of nanoparticles due to their innate long circulation property. Adipocytes, especially cancer-associated adipocytes, play key roles in tumor development and metabolism, therefore, adipocytes are regarded as promising bio-derived nanoplatforms for anticancer targeted drug delivery. Nanomaterials are important participants in cell-based drug delivery because of their unique physicochemical characteristics. Therefore, the integration of various nanomaterials with different cell types will endow the constructed delivery systems with many attractive properties due to the merits of both. In this review, a number of strategies based on nanomaterial-involved cell-mediated drug delivery systems for cancer treatment will be summarized. This review discusses how nanomaterials can be a benefit to cell-based therapies and how cell-derived carriers overcome the limitations of nanomaterials, which highlights recent advancements and specific biomedical applications based on nanomaterial-mediated, cell-based drug delivery systems.

High-density lipoproteins: A promising tool against cancer

High-density lipoproteins (HDL) are well known for their protective role against the development and progression of atherosclerosis. Atheroprotection is mainly due to the key role of HDL within the reverse cholesterol transport, and to their ability to exert a series of antioxidant and anti-inflammatory activities. Through the same mechanisms HDL could also affect cancer cell proliferation and tumor progression. Many types of cancers share common alterations of cellular metabolism, including lipid metabolism. In this context, not only fatty acids but also cholesterol and its metabolites play a key role. HDL were shown to reduce cancer cell content of cholesterol, overall rewiring cholesterol homeostasis. In addition, HDL reduce oxidative stress and the levels of pro-inflammatory molecules in cancer cells and in the tumor microenvironment (TME). Here, HDL can also help in reverting tumor immune escape and in inhibiting angiogenesis. Interestingly, HDL are good candidates for drug delivery, targeting antineoplastic agents to the tumor mass mainly through their binding to the scavenger receptor BI. Since they could affect cancer development and progression per se, HDL-based drug delivery systems may render cancer cells more sensitive to antitumor agents and reduce the development of drug resistance.

Nanoparticle-Mediated Targeted Drug Delivery to Remodel Tumor Microenvironment for Cancer Therapy

Advanced research has revealed the crucial role of tumor microenvironment (TME) in tumorigenesis. TME consists of a complicated network with a variety of cell types including endothelial cells, pericytes, immune cells, cancer-associated fibroblasts (CAFs), cancer stem cells (CSCs) as well as the extracellular matrix (ECM). The TME-constituting cells interact with the cancerous cells through plenty of signaling mechanisms and pathways in a dynamical way, participating in tumor initiation, progression, metastasis, and response to therapies. Hence, TME is becoming an attractive therapeutic target in cancer treatment, exhibiting potential research interest and clinical benefits. Presently, the novel nanotechnology applied in TME regulation has made huge progress. The nanoparticles (NPs) can be designed as demand to precisely target TME components and to inhibit tumor progression through TME modulation. Moreover, nanotechnology-mediated drug delivery possesses many advantages including prolonged circulation time, enhanced bioavailability and decreased toxicity over traditional therapeutic modality. In this review, update information on TME remodeling through NPs-based targeted drug delivery strategies for anticancer therapy is summarized.

Black Phosphorus, an Emerging Versatile Nanoplatform for Cancer Immunotherapy

Black phosphorus (BP) is one of the emerging versatile nanomaterials with outstanding biocompatibility and biodegradability, exhibiting great potential as a promising inorganic nanomaterial in the biomedical field. BP nanomaterials possess excellent ability for valid bio-conjugation and molecular loading in anticancer therapy. Generally, BP nanomaterials can be classified into BP nanosheets (BPNSs) and BP quantum dots (BPQDs), both of which can be synthesized through various preparation routes. In addition, BP nanomaterials can be applied as photothermal agents (PTA) for the photothermal therapy (PTT) due to their high photothermal conversion efficiency and larger extinction coefficients. The generated local hyperpyrexia leads to thermal elimination of tumor. Besides, BP nanomaterials are capable of producing singlet oxygen, which enable its application as a photosensitizer for photodynamic therapy (PDT). Moreover, BP nanomaterials can be oxidized and degraded to nontoxic phosphonates and phosphate under physiological conditions, improving their safety as a nano drug carrier in cancer therapy. Recently, it has been reported that BP-based PTT is capable of activating immune responses and alleviating the immunosuppressive tumor microenvironment by detection of T lymphocytes and various immunocytokines, indicating that BP-based nanocomposites not only serve as effective PTAs to ablate large solid tumors but also function as an immunomodulation agent to eliminate discrete tumorlets. Therefore, BP-mediated immunotherapy would provide more possibilities for synergistic cancer treatment.

Peptide-Targeted High-Density Lipoprotein Nanoparticles for Combinatorial Treatment against Metastatic Breast Cancer

The sonic hedgehog (SHH) signaling pathway exhibits aberrant activation in triple-negative breast cancer (TNBC), wherein it regulates several malignant phenotypes related to tumor metastasis. GANT61, an inhibitor of the SHH signaling pathway, may offer promise when administered in combination with conventional chemotherapy to treat metastatic TNBC. However, poor bioavailability and substantial off-target toxicity limit its clinical application. To address these limitations, we designed a peptide-functionalized dual-targeting delivery system encapsulating paclitaxel and GANT61 in tLyP-1 peptide-modified reconstituted high-density lipoprotein nanoparticle (tLyP-1-rHDL-PTX/GANT61 NP) for metastatic TNBC treatment. The apolipoprotein A-1 and tLyP-1 peptide modified on the surface of nanoparticles enable the delivery system to target tumor cells by binding to the overexpressed scavenger receptor B type I and neuropilin-1 receptor. Moreover, the tLyP-1 peptide also enables the deep tumor penetration of nanoparticles further facilitating paclitaxel and GANT61 delivery. Increased cellular uptake of the nanoparticles was observed in both MDA-MB-231, BT-549 tumor cells, and their 3D tumor spheroids. A series of in vitro experiments reveal that GANT61 was able to suppress key metastasis-related tumor cell activities including angiogenesis, migration, invasion, and stemness. Owing to more effective drug administration, the metastasis suppression efficiency of GANT61 was significantly enhanced by the dual-targeting tLyP-1-rHDL delivery system. Meanwhile, the codelivery of paclitaxel and GANT61 by dual-targeting tLyP-1-rHDL nanoparticles demonstrated superior efficiency of disrupting proliferation and inducing apoptosis in tumor cells compared with drug solutions. In a spontaneous metastasis breast cancer NCG mice model, the tLyP-1-rHDL-PTX/GANT61 nanoparticles exhibited highly tumor-specific distribution and result in significant inhibition of the primary tumor growth and dramatic reduction of lung metastasis without obvious side effects. The present work suggests that a combination of the SHH signaling pathway suppression and chemotherapy assisted by peptide-functionalized targeting tLyP-1-rHDL nanoparticles may provide a promising strategy for metastatic TNBC treatment.

Advanced and Innovative Nano-Systems for Anticancer Targeted Drug Delivery

The encapsulation of therapeutic agents into nano-based drug delivery system for cancer treatment has received considerable attention in recent years. Advancements in nanotechnology provide an opportunity for efficient delivery of anticancer drugs. The unique properties of nanoparticles not only allow cancer-specific drug delivery by inherent passive targeting phenomena and adopting active targeting strategies, but also improve the pharmacokinetics and bioavailability of the loaded drugs, leading to enhanced therapeutic efficacy and safety compared to conventional treatment modalities. Small molecule drugs are the most widely used anticancer agents at present, while biological macromolecules, such as therapeutic antibodies, peptides and genes, have gained increasing attention. Therefore, this review focuses on the recent achievements of novel nano-encapsulation in targeted drug delivery. A comprehensive introduction of intelligent delivery strategies based on various nanocarriers to encapsulate small molecule chemotherapeutic drugs and biological macromolecule drugs in cancer treatment will also be highlighted.

The Endothelium Is Both a Target and a Barrier of HDL's Protective Functions

The vascular endothelium serves as a barrier between the intravascular and extravascular compartments. High-density lipoproteins (HDL) have two kinds of interactions with this barrier. First, bloodborne HDL must pass the endothelium to access extravascular tissues, for example the arterial wall or the brain, to mediate cholesterol efflux from macrophages and other cells or exert other functions. To complete reverse cholesterol transport, HDL must even pass the endothelium a second time to re-enter circulation via the lymphatics. Transendothelial HDL transport is a regulated process involving scavenger receptor SR-BI, endothelial lipase, and ATP binding cassette transporters A1 and G1. Second, HDL helps to maintain the integrity of the endothelial barrier by (i) promoting junction closure as well as (ii) repair by stimulating the proliferation and migration of endothelial cells and their progenitor cells, and by preventing (iii) loss of glycocalix, (iv) apoptosis, as well as (v) transmigration of inflammatory cells. Additional vasoprotective functions of HDL include (vi) the induction of nitric oxide (NO) production and (vii) the inhibition of reactive oxygen species (ROS) production. These vasoprotective functions are exerted by the interactions of HDL particles with SR-BI as well as specific agonists carried by HDL, notably sphingosine-1-phophate (S1P), with their specific cellular counterparts, e.g., S1P receptors. Various diseases modify the protein and lipid composition and thereby the endothelial functionality of HDL. Thorough understanding of the structure-function relationships underlying the multiple interactions of HDL with endothelial cells is expected to elucidate new targets and strategies for the treatment or prevention of various diseases.