Amine-functionalized poly(lactic-co-glycolic acid) nanoparticles for improved cellular uptake and tumor penetration

Engineered microbubbles decorated with red emitting carbon nanoparticles for efficient delivery and imaging

Altering the route of uptake by the cells is an attractive strategy to overcome drug-receptor adaptation problems. Carbon nanoparticles (CNPs) with emission beyond tissue autofluorescence for imaging biological tissues were used to study the phenomenon of uptake by the cells. In this regard, red-emitting carbon nanoparticles (CNPs) were synthesized and incorporated onto lipid microbubbles (MBs). The CNPs showed red emissions in the range of 640 nm upon excitation with 480 nm wavelength of light. Atomic force microscopic and confocal microscopic images showed the successful loading of CNPs onto the MB. Carbon nanoparticle loaded microbubbles (CNP-MBs) were treated with NIH 3 T3 cells at different concentrations. Confocal microscopic imaging studies confirm the presence of CNPs inside the treated cells. Cytotoxicity studies revealed that the CNPs showed minimal toxicity towards cells after loading onto MBs. The CNPs are usually taken up by the cells through the clathrin-mediated (CME) pathway, but when loaded onto MBs, the mechanism of uptake of CNPs is altered, and the uptake by the cells was observed even in the presence of inhibitors for the CME pathway. Loading CNPs onto MBs resulted in the uptake of CNPs by the cell through micropinocytosis and sonophoresis in the presence of ultrasound. The in vivo uptake CNP-MBs were performed in Danio rerio (Zebrafish larvae). This study provides insights into altering the uptake pathway through reformulation by loading nanoparticles onto MBs.

Phloretin, as a Potent Anticancer Compound: From Chemistry to Cellular Interactions

Phloretin is a natural dihydrochalcone found in many fruits and vegetables, especially in apple tree leaves and the Manchurian apricots, exhibiting several therapeutic properties, such as antioxidant, antidiabetic, anti-inflammatory, and antitumor activities. In this review article, the diverse aspects of the anticancer potential of phloretin are addressed, presenting its antiproliferative, proapoptotic, antimetastatic, and antiangiogenic activities in many different preclinical cancer models. The fact that phloretin is a planar lipophilic polyphenol and, thus, a membrane-disrupting Pan-Assay Interference compound (PAIN) compromises the validity of the cell-based anticancer activities. Phloretin significantly reduces membrane dipole potential and, therefore, is expected to be able to activate a number of cellular signaling pathways in a non-specific way. In this way, the effects of this minor flavonoid on Bax and Bcl-2 proteins, caspases and MMPs, cytokines, and inflammatory enzymes are all analyzed in the current review. Moreover, besides the anticancer activities exerted by phloretin alone, its co-effects with conventional anticancer drugs are also under discussion. Therefore, this review presents a thorough overview of the preclinical anticancer potential of phloretin, allowing one to take the next steps in the development of novel drug candidates and move on to clinical trials.

Extended transit compartment model to describe tumor delay using Coxian distribution

The measured response of cell population is often delayed relative to drug injection, and individuals in a population have a specific age distribution. Common approaches for describing the delay are to apply transit compartment models (TCMs). This model reflects that all damaged cells caused by drugs suffer transition processes, resulting in death. In this study, we present an extended TCM using Coxian distribution, one of the phase-type distributions. The cell population attacked by a drug is described via age-structured models. The mortality rate of the damaged cells is expressed by a convolution of drug rate and age density. Then applying to Erlang and Coxian distribution, we derive Erlang TCM, representing the existing model, and Coxian TCMs, reflecting sudden death at all ages. From published data of drug and tumor, delays are compared after parameter estimations in both models. We investigate the dynamical changes according to the number of the compartments. Model robustness and equilibrium analysis are also performed for model validation. Coxian TCM is an extended model considering a realistic case and captures more diverse delays.

Nanostructured lipid carriers for the encapsulation of phloretin: preparation and in vitro characterization studies

Phloretin is a powerful antioxidant with many effects, such as anti-cancer, anti-inflammatory, promoting cell renewal, delaying aging and so on. However, the application of phloretin was limited by its low water solubility, low absorption in vivo and unstable properties. A phloretin-loaded nanostructured lipid carrier was designed with a high-pressure homogenization technique. The mean particle size of phloretin NLC was 137.40 ± 3.27 nm, and the Polydispersity index (PdI) value was 0.237 ± 0.005. The encapsulation efficiency was 96.68% ± 0.06%. Transmission electron microscopy images showed that the phloretin-loaded nanostructured lipid carriers were spherical. Phloretin in NLC showed a sustained release pattern in vitro. The results showed that phloretin NLC is more suitable for absorption than phloretin ethanol solution, and NLC can be a promising carrier for phloretin in the food industry.

Innovative hydrogel containing polymeric nanocapsules loaded with phloretin: Enhanced skin penetration and adhesion

Dermatological applications of phloretin are restricted by its poor aqueous solubility. Nanotechnology has been proposed as strategy to increase the apparent drug solubility in aqueous media. This study aimed to develop, characterize, and evaluate the antitumoral effects and safety of polymeric nanocapsules containing phloretin (NCPhl). Further, to incorporate NC-Phl in an innovative semi-solid formulation (HG-NCPhl) to evaluate its performance using porcine skin model. NC-Phl was prepared and the effects in MRC5, HACAT, and SK-mel28 cells were evaluated. Hydrogels were prepared with Lecigel ® and characterized for their nanotechnological properties, adhesion (in vitro washability), and penetration/permeation studies in porcine skin. NC-Phl had a cytotoxic effect against Sk-Mel-28 cells and the population doubling time was increased upon treatment with NC-Phl for longer culture periods; notably when cells were treated for 72 h and then followed for 7 days after the treatment was removed (p < 0.05). HG-NC-Phl was considered adhesive and had a higher capacity to penetrate all skin layers compared with HG-Phl (p < 0.05). The innovative hydrogel HGNC-Phl promoted a drug-reservoir in the stratum corneum and higher penetration of the flavonoid into the epidermis. Therefore, this approach can be considered as a platform to establish versatile dermatological solutions for both cosmeceutics and melanoma therapy.

Dermatological applications of the flavonoid phloretin

Botanical molecules are known to have the ability to counteract ultraviolet radiation-induced skin damage. The interest in the development of natural compound-based products for the prevention of solar ultraviolet radiation-induced skin photoaging, melasma, and photocarcinogenesis has been increasing. Recently, the flavonoid phloretin has attracted the attention of researchers in the dermatological field for application in cosmetics and therapeutics. In addition to its antioxidant activity, phloretin has been shown to have properties such as anti-aging and depigmenting effects. In this study, we review the dermatological treatments with phloretin for conditions such as melasma, photoaging, acne, and melanoma. Phloretin has been shown to inhibit elastase and matrix metalloproteinase-1 activity, to reduce cellular tyrosinase activity and melanin content, and induce apoptosis in B16 mouse melanoma 4A5 cells. An in vivo study showed that phloretin, applied topically to the dorsal skin of mice, suppressed the 12-O-tetradecanoylphorbol 13-acetate-induced expression of COX-2, a critical molecular target of many chemopreventive, as well as anti-inflammatory agents. Phloretin can penetrate the skin; nevertheless, its penetration profile in different skin layers has not yet been evaluated. Despite its health benefits, phloretin application has been limited because of its photoinstability and poor aqueous solubility, among other limitations. Therefore, we reviewed the recent advances in pharmaceutical applications such as the use of nanotechnology, in order to improve the cutaneous availability of phloretin. In this review, we also focus on the oral application, product development challenges, and recent progress and future research directions on phloretin.

Possible contribution of sialic acid to the enhanced tumor targeting efficiency of nanoparticles engineered with doxorubicin

Doxorubicin (DOX)-engineered poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) including phloretin (PHL) were designed and the feasible contribution of sialic acid (SA) to the improved tumor targeting and penetration capabilities was elucidated in lung adenocarcinoma models. DOX has been clinically used as liposomal formulations after its introduction to the inner side of vehicles, however DOX is anchored in the outer surface of PLGA NPs for improved tumor penetration by interactions with SA in this study. DOX (positively charged at physiological pH) was adsorbed onto the negatively charged PLGA NPs via electrostatic interactions and consequent binding of SA (negatively charged at physiological pH) to DOX located in NPs was also elucidated. DOX layer in DOX@PLGA NPs rendered improved endocytosis and partial contribution of SA (expressed in cancer cells) to that endocytosis was demonstrated. DOX@PLGA/PHL NPs provided enhanced antiproliferation potentials in A549 cells rather than single agent (DOX or PHL)-installed NPs. In addition, DOX-SA interactions seemed to play critical roles in tumor infiltration and accumulation of DOX@PLGA NPs in A549 tumor-xenografted mouse model. All these findings support the novel use of DOX which is used for the surface engineering of NPs for improved tumor targeting and penetration.

Recent Progress in the Development of Poly(lactic-co-glycolic acid)-Based Nanostructures for Cancer Imaging and Therapy

Diverse nanosystems for use in cancer imaging and therapy have been designed and their clinical applications have been assessed. Among a variety of materials available to fabricate nanosystems, poly(lactic-co-glycolic acid) (PLGA) has been widely used due to its biocompatibility and biodegradability. In order to provide tumor-targeting and diagnostic properties, PLGA or PLGA nanoparticles (NPs) can be modified with other functional materials. Hydrophobic or hydrophilic therapeutic cargos can be placed in the internal space or adsorbed onto the surface of PLGA NPs. Protocols for the fabrication of PLGA-based NPs for cancer imaging and therapy are already well established. Moreover, the biocompatibility and biodegradability of PLGA may elevate its feasibility for clinical application in injection formulations. Size-controlled NP’s properties and ligand–receptor interactions may provide passive and active tumor-targeting abilities, respectively, after intravenous administration. Additionally, the introduction of several imaging modalities to PLGA-based NPs can enable drug delivery guided by in vivo imaging. Versatile platform technology of PLGA-based NPs can be applied to the delivery of small chemicals, peptides, proteins, and nucleic acids for use in cancer therapy. This review describes recent findings and insights into the development of tumor-targeted PLGA-based NPs for use of cancer imaging and therapy.

Application of temporary agglomeration of chitosan-coated nanoparticles for the treatment of lung metastasis of melanoma

Temporary association of chitosan (CS)-coated nanoparticles (NPs) including phloretin (Phl) in the blood stream can be applied to treat lung metastasis of melanoma. Phl was entrapped in poly(d,l-lactide-co-glycolide) (PLGA) NPs as an anticancer agent, whereas CS was decorated onto the outer surfaces of the Phl-loaded PLGA NPs (PLGA/Phl NPs). CS-coated PLGA/Phl NPs (CS-PLGA/Phl NPs) with mean hydrodynamic sizes of 342 nm, spherical shapes, unimodal size distribution, positive zeta potentials, and drug encapsulation efficiency larger than 90% were prepared. The presence of the CS layers in the outer surfaces of the CS-PLGA/Phl NPs was elucidated by X-ray photoelectron spectroscopy. Upon blending of the CS-PLGA/Phl NPs with serum albumin, microscale agglomerates formed and easily dissociated into individual NPs by applying external forces. A sustained Phl release from NPs and similar antiproliferation potential of the CS-PLGA/Phl NPs to that of Phl in melanoma (B16F10) cells were observed. After multiple dosing of developed NPs in mouse models with lung metastasis of melanoma, the CS-PLGA/Phl NPs group exhibited significantly lower lung weight and number of metastasis foci than the PLGA/Phl NPs group (p < 0.05). These results suggest that the transient transformation of NPs into microscale aggregates and their facile dissociation into individual NPs can be efficiently and safely applied for the treatment of lung metastasis of melanoma.

A potential carrier for anti-tumor targeted delivery-hyaluronic acid nanoparticles

In recent years, biomacromolecules have been widely used in anti-tumor delivery systems due to the biocompatibility and biodegradability. However, their applications are limited due to the lack of specific targeting. Hyaluronic acid (HA) is a natural polysaccharide and presents in extracellular matrix and synovial fluid which can specifically recognize receptors over-expressed by tumor cells. In addition, they can self-assemble into nanoparticles. HA nanoparticles provide new hierarchical targeting strategies: passively targeting tumor tissue by enhanced permeability and retention effect, actively targeting tumor cells by cluster determinant 44 (CD44) receptor, and then entering cells through receptor-mediated endocytosis. In this review, the synthesis of HA nanoparticles is described in detail from several aspects and applications are also discussed for improving the delivery of hydrophobic drugs, nucleic acids and photosensitizers into the tumor cells. In addition, the modification of HA for improving the targeting and drug releasing characteristics are also discussed.

Biotin-Modified Polylactic- co-Glycolic Acid Nanoparticles with Improved Antiproliferative Activity of 15,16-Dihydrotanshinone I in Human Cervical Cancer Cells

15,16-Dihydrotanshinone I (DI), a natural compound isolated from a traditional Asian functional food Salvia Miltiorrhiza Bunge, is known for its anticancer activity. However, poor solubility of DI limits its desirable anticancer application. Herein, polylactic- co-glycolic acid (PLGA) was functionalized with polyethylene glycol (PEG) and biotin to form copolymers PEG-PLGA (PPA) and biotin-PEG-PLGA (BPA). DI was encapsulated in copolymers PPA and BPA to obtain DI-PPA-NPs (NPs = nanoparticles) and DI-BPA-NPs, respectively. The particle size and its distribution, encapsulation efficiency, and in vitro releasing capacity of DI-BPA-NPs were characterized by biophysical methods. MTT assay was used to evaluate the antiproliferative activity of free DI, DI-PPA-NPs, and DI-BPA-NPs in human cervical cancer Hela cells. DI-BPA-NPs showed the highest cytotoxicity on Hela cells with an IC₅₀ value of 4.55 ± 0.631 μM, while it was 8.20 ± 0.849 and 6.14 ± 0.312 μM for DI and DI-PPA-NPs in 72 h, respectively. The superior antiproliferative activity was supported by the fact that DI-BPA-NPs could be preferentially internalized by Hela cells, owing to their specific interaction between biotin and overexpressed biotin receptors. In addition, DI-BPA-NPs effectively inhibited Hela cell proliferation by inducing G2/M phase cycle arrest and decreasing the intracellular reactive oxygen species (ROS) level by 31.50 ± 2.29% in 5 min. In summary, DI-BPA-NPs shows improved antiproliferative activity against human cervical cancer as comparing with free DI, demonstrating its application potential in cancer therapy.

Development of Resveratrol-Loaded Herbal Extract-Based Nanocomposites and Their Application to the Therapy of Ovarian Cancer

Resveratrol (RSV) and the ethanol extract of Angelica gigas Nakai (AGN Ex)-based nanoparticles (NPs) were prepared using the nanocrystal concept. AGN/RSV NPs with 224 nm hydrodynamic size, unimodal size distribution, and negative zeta potential values were developed with the emulsification and solvent evaporation techniques. The crystalline properties of AGN Ex and RSV were transformed during the emulsification and solvent evaporation processes, thus, AGN NPs and AGN/RSV NPs exhibited amorphous states. AGN/RSV NPs held up their initial hydrodynamic size after 24 h of incubation in serum-included media. Sustained release profiles (for 5 days) of decursin (D) and decursinol angelate (DA) (the representative markers of AGN Ex) and RSV were observed at normal physiological pH (pH 7.4). In ovarian cancer (SKOV-3) cells, although AGN/RSV NPs showed a lower cellular entry rate rather than AGN NPs, the cellular accumulated amount of AGN/RSV NPs was similar with that of AGN NPs after 4 h of incubation. The antiproliferation efficiency of AGN/RSV NPs group was significantly higher than the AGN Ex, AGN NPs, and AGN NPs + RSV groups in SKOV-3 cells. AGN/RSV NPs can be one of the promising candidates for therapeutic nanoplatforms against ovarian cancers.

Berberine and zinc oxide-based nanoparticles for the chemo-photothermal therapy of lung adenocarcinoma

Organic/inorganic hydrid nanoparticles (NPs) composed of berberine (BER) and zinc oxide (ZnO) were developed for the therapy of lung cancers. Without the use of pharmaceutical excipients, NPs were fabricated with only dual anticancer agents (BER and ZnO) by facile blending method. The mean weight ratio between BER and ZnO in BER-ZnO NPs was 39:61 in this study. BER-ZnO NPs dispersed in water exhibited 200-300 nm hydrodynamic size under 5 mg/mL concentration. The exposure of both BER and ZnO in the outer layers of BER-ZnO NPs was identified by X-ray photoelectron spectroscopy analysis. The amorphization of BER and the maintenance of ZnO structure were observed in the results of X-ray powder diffractometer analysis. Improved antiproliferation efficacy, based on the chemo-photothermal therapeutic efficacy, of BER-ZnO NPs in A549 (human lung adenocarcinoma) cells was presented. According to the blood tests in rats after intravenous administration, BER-ZnO NPs did not induce severe hepatotoxicity, renal toxicity, and hemotoxicity. Developed BER-ZnO NPs can be used efficiently and safely for the chemo-photothermal therapy of lung cancers.

Strategies for the enhanced intracellular delivery of nanomaterials

The intracellular delivery of nanomaterials and drugs has been attracting increasing research interest, mainly because of their important effects and functions in several organelles. Targeting specific organelles can help treat or decrease the symptoms of diabetes, cancer, infectious, and autoimmune diseases. Tuning biological and chemical properties enables the creation of functionalized nanomaterials with enhanced intracellular uptake, ability to escape premature lysosome degradation, and to reach a specific target. Here, we provide an update of recent advances in the intracellular delivery mechanisms that could help drugs reach their target more efficiently.

Multicellular Tumor Spheroids (MCTS) as a 3D In Vitro Evaluation Tool of Nanoparticles

Multicellular tumor spheroid models (MCTS) are often coined as 3D in vitro models that can mimic the microenvironment of tissues. MCTS have gained increasing interest in the nano-biotechnology field as they can provide easily accessible information on the performance of nanoparticles without using animal models. Considering that many countries have put restrictions on animals testing, which will only tighten in the future as seen by the recent developments in the Netherlands, 3D models will become an even more valuable tool. Here, an overview on MCTS is provided, focusing on their use in cancer research as most nanoparticles are tested in MCTS for treatment of primary tumors. Thereafter, various types of nanoparticles-from self-assembled block copolymers to inorganic nanoparticles, are discussed. A range of physicochemical parameters including the size, shape, surface chemistry, ligands attachment, stability, and stiffness are found to influence nanoparticles in MCTS. Some of these studies are complemented by animal studies confirming that lessons from MCTS can in part predict the behaviour in vivo. In summary, MCTS are suitable models to gain additional information on nanoparticles. While not being able to replace in vivo studies, they can bridge the gap between traditional 2D in vitro studies and in vivo models.

Polydopamine-coated nanocomposites of Angelica gigas Nakai extract and their therapeutic potential for triple-negative breast cancer cells

Polydopamine (PD)-coated nanocomposites (NCs) based on the ethanol extract of Angelica gigas Nakai (AGN EtOH ext) were fabricated and evaluated for breast cancer therapy. AGN NCs were prepared using a modified emulsification-solvent evaporation method and were further incubated in dopamine solution (at pH 8.6) to be covered with the PD layer. PD-AGN NCs with a 213-nm mean diameter, narrow size distribution, and negative zeta potential values were fabricated in this study. Less negative (close to zero) zeta potential value of PD-AGN NCs than that of AGN NCs implied the existence of the PD layer in the outer surface of NCs. The PD layer in PD-AGN NCs was also identified by X-ray photoelectron spectroscopy (XPS) and ultraviolet (UV)/visible absorption analyses. The sustained release of decursin (D) and decursinol angelate (DA), as major active pharmacological components of AGN, was observed in both AGN NCs and PD-AGN NCs. Enhanced cellular binding property of PD-AGN NCs, compared to AGN NCs, in MDA-MB-231 (human breast adenocarcinoma; triple-negative breast cancer) cells was observed. Improved anticancer activities of PD-AGN NCs compared with those of AGN EtOH ext and AGN NCs were also shown in MDA-MB-231 cells. The developed PD-AGN NCs may be used as remarkable platform nanocarriers for efficient breast cancer therapy.

Poly((D,L)lactic-glycolic)acid-star glucose nanoparticles for glucose transporter and hypoglycemia-mediated tumor targeting

Poly((D,L)lactic-glycolic)acid-star glucose (PLGA-Glc) polymer-based nanoparticles (NPs) were fabricated for tumor-targeted delivery of docetaxel (DCT). NPs with an approximate mean diameter of 241 nm, narrow size distribution, negative zeta potential, and spherical shape were prepared. A sustained drug release pattern from the developed NPs was observed for 13 days. Moreover, drug release from PLGA-Glc NPs at acidic pH (endocytic compartments and tumor regions) was significantly improved compared with that observed at physiological pH (normal tissues and organs). DCT-loaded PLGA-Glc NPs (DCT/PLGA-Glc NPs) exhibited an enhanced antiproliferation efficiency rather than DCT-loaded PLGA NPs (DCT/PLGA NPs) in Hep-2 cells, which can be regarded as glucose transporters (GLUTs)-positive cells, at ≥50 ng/mL DCT concentration range. Under glucose-deprived (hypoglycemic) conditions, the cellular uptake efficiency of the PLGA-Glc NPs was higher in Hep-2 cells compared to that observed in PLGA NPs. Cy5.5-loaded NPs were prepared and injected into a Hep-2 tumor-xenografted mouse model for in vivo near-infrared fluorescence imaging. The PLGA-Glc NPs group exhibited higher fluorescence intensity in the tumor region than the PLGA NPs group. These results imply that the PLGA-Glc NPs have active tumor targeting abilities based on interactions with GLUTs and the hypoglycemic conditions in the tumor region. Therefore, the developed PLGA-Glc NPs may represent a promising tumor-targeted delivery system for anticancer drugs.

Distribution of PLGA-modified nanoparticles in 3D cell culture models of hypo-vascularized tumor tissue

BACKGROUND

Advanced stage cancer treatments are often invasive and painful-typically comprised of surgery, chemotherapy, and/or radiation treatment. Low transport efficiency during systemic chemotherapy may require high chemotherapeutic doses to effectively target cancerous tissue, resulting in systemic toxicity. Nanotherapeutic platforms have been proposed as an alternative to more safely and effectively deliver therapeutic agents directly to tumor sites. However, cellular internalization and tumor penetration are often diametrically opposed, with limited access to tumor regions distal from vasculature, due to irregular tissue morphologies. To address these transport challenges, nanoparticles (NPs) are often surface-modified with ligands to enhance transport and longevity after localized or systemic administration. Here, we evaluate stealth polyethylene-glycol (PEG), cell-penetrating (MPG), and CPP-stealth (MPG/PEG) poly(lactic-co-glycolic-acid) (PLGA) NP co-treatment strategies in 3D cell culture representing hypo-vascularized tissue.

RESULTS

Smaller, more regularly-shaped avascular tissue was generated using the hanging drop (HD) method, while more irregularly-shaped masses were formed with the liquid overlay (LO) technique. To compare NP distribution differences within the same type of tissue as a function of different cancer types, we selected HeLa, cervical epithelial adenocarcinoma cells; CaSki, cervical epidermoid carcinoma cells; and SiHa, grade II cervical squamous cell carcinoma cells. In HD tumors, enhanced distribution relative to unmodified NPs was measured for MPG and PEG NPs in HeLa, and for all modified NPs in SiHa spheroids. In LO tumors, the greatest distribution was observed for MPG and MPG/PEG NPs in HeLa, and for PEG and MPG/PEG NPs in SiHa spheroids.

CONCLUSIONS

Pre-clinical evaluation of PLGA-modified NP distribution into hypo-vascularized tumor tissue may benefit from considering tissue morphology in addition to cancer type.

Fabrication of polymer matrix-free nanocomposites based on Angelica gigas Nakai extract and their application to breast cancer therapy

Nanocomposites (NCs) based on the ethanol extract of Angelica gigas Nakai (AGN EtOH ext) were developed for breast cancer therapy. Polymer matrix-free nano-sized particles based on the extract of natural product were fabricated using a modified emulsification-solvent evaporation method. Without the use of polymer matrix, toxicity can be minimized and the clinical application may be assured. AGN NCs with approximately 200nm mean diameter, narrow size distribution, and negative zeta potential were prepared in this study. Sustained release of decursin (D) and decursinol angelate (DA) (as major components of AGN) from AGN NCs was observed at pH 7.4. Cellular accumulation efficiency and intracellular distribution of AGN NCs were evaluated in MCF-7 (human breast adenocarcinoma) cells. According to the results of antiproliferation assay in MCF-7 cells, IC₅₀ value of AGN NCs group (27.4±4.0μg/mL) was lower than that of AGN EtOH ext group (75.3±13.7μg/mL) (p<0.05). Also, the percentage of apoptotic events of AGN NCs group was significantly higher than that of AGN EtOH ext group (p<0.05). All these findings suggest that developed AGN NCs can be used as one of promising nanosystems for the therapy of breast cancers.

Boronic acid-tethered amphiphilic hyaluronic acid derivative-based nanoassemblies for tumor targeting and penetration

(3-Aminomethylphenyl)boronic acid (AMPB)-installed hyaluronic acid-ceramide (HACE)-based nanoparticles (NPs), including manassantin B (MB), were fabricated for tumor-targeted delivery. The amine group of AMPB was conjugated to the carboxylic acid group of hyaluronic acid (HA) via amide bond formation, and synthesis was confirmed by spectroscopic methods. HACE-AMPB/MB NPs with a 239-nm mean diameter, narrow size distribution, negative zeta potential, and >90% drug encapsulation efficiency were fabricated. Exposed AMPB in the outer surface of HACE-AMPB NPs (in the aqueous environment) may react with sialic acid of cancer cells. The improved cellular accumulation efficiency, in vitro antitumor efficacy, and tumor penetration efficiency of HACE-AMPB/MB NPs, compared with HACE/MB NPs, in MDA-MB-231 cells (CD44 receptor-positive human breast adenocarcinoma cells) may be based on the CD44 receptor-mediated endocytosis and phenylboronic acid-sialic acid interaction. Enhanced in vivo tumor targetability, infiltration efficiency, and antitumor efficacies of HACE-AMPB NPs, compared with HACE NPs, were observed in a MDA-MB-231 tumor-xenografted mouse model. In addition to passive tumor targeting (based on an enhanced permeability and retention effect) and active tumor targeting (interaction between HA and CD44 receptor), the phenylboronic acid-sialic acid interaction can play important roles in augmented tumor targeting and penetration of HACE-AMPB NPs. STATEMENT OF SIGNIFICANCE: (3-Aminomethylphenyl)boronic acid (AMPB)-tethered hyaluronic acid-ceramide (HACE)-based nanoparticles (NPs), including manassantin B (MB), were fabricated and their tumor targeting and penetration efficiencies were assessed in MDA-MB-231 (CD44 receptor-positive human adenocarcinoma) tumor models. MB, which exhibited antitumor efficacies via the inhibition of angiogenesis and hypoxia inducible factor (HIF)-1, was entrapped in HACE-AMPB NPs in this study. Phenylboronic acid located in the outer surface of HACE-AMPB/MB NPs (in the aqueous milieu) may react with the sialic acid over-expressed in cancer cells and intramolecular B‒O bond can be formed. This phenylboronic acid-sialic acid interaction may provide additional tumor targeting and penetration potentials together with an enhanced permeability and retention (EPR) effect (passive tumor targeting) and HA-CD44 receptor interaction (active tumor targeting). Developed HACE-AMPB NP may be one of promising nanocarriers for the imaging and therapy of CD44 receptor-expressed cancers.

Dopamine-conjugated poly(lactic-co-glycolic acid) nanoparticles for protein delivery to macrophages

Poly(lactic-co-glycolic acid)-dopamine (PLGA-D)-based nanoparticles (NPs) were developed for the delivery of protein to macrophages. PLGA-D was synthesized via amide bond formation between the amine group of D and the carboxylic acid group of PLGA. Bovine serum albumin (BSA, model protein) was encapsulated in PLGA NPs and PLGA-D NPs, which had an approximately 200nm mean diameter, <0.2 polydispersity index, and negative zeta potential value. There was no increment in the mean diameters of BSA-loaded NPs after 24h of incubation in biological fluid-simulated media (i.e., aqueous buffer and serum media). The primary, secondary, and tertiary structures of BSA released from the NPs were studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), circular dichroism, and fluorescence spectrophotometry; the structural stability of BSA was preserved during its encapsulation in the NPs and release from the NPs. PLGA/BSA NPs and PLGA-D/BSA NPs did not induce serious cytotoxicity in RAW 264.7 cells (mouse macrophage cell line) in an established concentration range. In RAW 264.7 cells, the intracellular accumulation of PLGA-D NPs was 2-fold higher than that of PLGA NPs. All of these findings indicated that PLGA-D NPs are a promising system for delivering proteins to macrophages.