Alamandine (Ala), a relatively recent addition to the renin-angiotensin system (RAS), is a heptapeptide sharing structural similarities with angiotensin-(1-7). This peptide has garnered significant attention due to its distinctive antihypertensive, vasodilatory, and antifibrotic effects. In this study, we sought to determine whether Ala acts as a counter-regulatory agent against angiotensin II-induced cardiac hypertrophy, fibrosis, and inflammation in rats. Male SD rats (n=6 in each group) received a two-week subcutaneous infusion of vehicle (saline), angiotensin II (ANG II, 150 ng/kg/min), or a combination of ANG II and Ala (50 ng/kg/min) via mini osmotic pumps. Left ventricular (LV) function was evaluated through echocardiography. Histological analysis of cardiac hypertrophy and fibrosis was conducted using Hematoxylin Eosin and Trichome-Mason staining, respectively. Compared to the vehicle group, treatment with Ala significantly (*p<0.05) attenuated ANG II-induced cardiac mass (659.27 ± 54.26* vs. 824.48 ± 40.38 mg) with reduced LV thickness and end-diastolic volume. Ala treatment also improved cardiac function, as indicated by reduced global longitudinal strain and myocardial performance index. Histological images revealed that Ala treatment markedly reduced cardiomyocyte area (383.63* ± 7.20 vs 490.59 ± 13.13 μm²) and fibrosis area (5.22* ± 0.93 vs. 9.64 ± 0.36%) in rats treated with ANG II, along with reduced mRNA expression of pro-hypertrophic markers such as brain natriuretic peptide (4.29 ± 0.50* vs 7.53 ± 0.68, fold change) and β-myosin heavy chain (6.11 ± 0.61* vs 10.29 ± 1.02), as well as pro-fibrosis markers collagen 1 (5.72 ± 0.59* vs 10.56 ± 1.69), fibronectin (2.18 ± 0.34* vs 4.69 ± 0.70), and α-smooth muscle actin (2.14 ± 0.42* vs 3.85 ± 0.06), when compared to the rats treated with ANG II alone. Flow cytometry analysis also showed that Ala treatment significantly reduced ANG II-induced immune responses in the heart by reducing immune cell populations including CD4, CD8 T cells, B cells and NK cells, and increasing presence of anti-inflammatory M2 monocytes. Additionally, the mRNA levels of interlukin-6, CD 68, and chemokine monocyte chemoattractant protein-1 were significantly decreased in Ala-treated rats. Furthermore, treatment with Ala reversed ANG II-induced alterations in the mRNA expression of angiotensin-converting enzyme (ACE, 2.05 ± 0.16* vs. 3.08 ± 0.25), angiotensin type 1 receptor (1.45 ± 0.22* vs. 2.56 ± 0.31), and ACE 2 (1.08 ± 0.10** vs. 0.38 ± 0.06) in the LV of the heart. Taken together, these findings demonstrate that alamandine exerts a protective effect against ANG II-induced cardiac dysfunction, hypertrophy, fibrosis, and inflammation, potentially acting as a protective component of the RAS to counteract the adverse effects of ANG II. Alamandine might be a potential therapeutic agent in the treatment of cardiovascular disorders. Supported by NIH grants R01 HL139521 & 155091. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Objective: Alamandine, a recently identified component of the renin-angiotensin system (RAS), is an endogenous heptapeptide derived from angiotensin-(1-7) or angiotensin A. Synthesized primarily through the enzymatic actions of angiotensin-converting enzyme 2 and aspartate decarboxylase, alamandine exerts its effects by binding to the Mas-related G protein-coupled receptor (MrgD). In contrast to the well-studied angiotensin II (ANG II), alamandine exhibits vasodilatory, anti-inflammatory, and anti-fibrotic properties, thereby representing a novel player in the cardioprotective axis of RAS, countering the detrimental effects associated with classical RAS activation. However, the role of alamandine in regulating sympathetic outflow remains unclear. Design and method: The present study sought to examine the effects of systemic alamandine on hemodynamic and sympathetic responses in rats and determine whether alamandine counteracts ANG II-caused hypertension. Blood pressure (BP, mmHg), heart rate (HR, beats/min), and renal sympathetic nerve activity (RSNA, % change) were recorded in urethane-anesthetized male Sprague Dawley rats. Results: While intravenous (IV) vehicle (n=6) did not induce a significant change, IV injection of alamandine (n=6) elicited a substantial (p<0.05) reduction in BP (from 91.5 ± 3.4 to 77.6 ± 3.1∗), HR (from 313 ± 7 to 274 ± 6∗), and RSNA (25.1 ± 2.4% change∗), beginning within 10-15 mins after IV injection. The responses peaked at 45-60 min and returned to baseline within 120 min. Additionally, while a two-week subcutaneous infusion of ANG II significantly elevated BP, concurrent treatment with alamandine obviously attenuated ANG II-induced pressor response (from 115.9 ± 4.7 to 90.1 ± 3.2∗). Conclusions: These results indicate that systemic alamandine has inhibitory effects on sympathetic drive and ANG II-induced hypertension. The diminished impact of alamandine on sympathetic outflow may play a role in the attenuation of pressor responses. Further study to elucidate its molecular mechanisms and physiological implications holds significant potential for advancing our understanding of RAS regulation and identifying novel therapeutic targets in the treatment of cardiovascular disorders such as hypertension and heart failure.

Intracellular delivery crossing the endomembrane barrier is the "last mile to target" for nano delivery systems carrying biomacromolecules, including genetic medicines. Nevertheless, a mass of nanomedicines is currently restricted by their equivocal safety and delivery efficiency. Here, we establish a universal strategy independent of nanomaterials. Such a policy broadly facilitates the intracellular delivery of all kinds of tested nanomedicines, subtly by inducing ARF6 GTPases to their overactivated GTP-bound state. ARF6, one member of ARF subfamily in small GTPases, is verified to regulate intracellular vesicle transport and lipid metabolism through GTP/GDP conversion. ARF6 biased to GTP-bound state causes the increased endocytosis and reduced exocytosis of eleven types of nanoparticles. This universal effect is derived from the formation of a hybrid type of endosomes triggered by overactivated ARF6 via regulating cholesterol-associated vesicles and lipid raft/caveolae pathways. Due to the mild microenvironment in hybrid endosomes, the internalized protein and nanoparticles are steadily delivered to the cytoplasm, avoiding the intensive degradation in lysosomes. Based on these findings, we identify QS11, a safe small molecule inhibitor of ARF GTPase-activating proteins, significantly enhances the antitumor efficacy of siEGFR-loaded nanoparticles by inducing ARF6 overactivation. In sum, these findings reveal that the tactics of tuning ARF6 GTPases to GTP-bound form will widely benefit cellular nano delivery.

Alamandine, a newly identified derivative of angiotensin II has been shown to exert antihypertensive and vasodilative actions, and may represent a novel component of cardioprotective axis of renin angiotensin system. We sought to determine the protective effects of alamandine on isoproterenol (ISO) induced cardiac remodeling and dysfunction in rats. Male SD rats (n=6 in each group) received a two-week subcutaneous infusion of vehicle, ISO (10 mg/kg/day) or a combination of ISO and alamandine (50 ng/kg/min). Compared with vehicle group, the ratio of heart/body weight (mg/g) in ISO treated rats was significantly (*P<0.05) elevated (3.93 ± 0.18 vs. 3.07 ± 0.08*), which was markedly attenuated by alamandine (3.50 ± 0.08*). Echocardiographic assessment showed that alamandine improved ISO-induced left ventricular (LV) dysfunction evidenced by reducing LV thickness (1.68 ± 0.07* vs 1.90 ± 0.02 mm), end diastolic and systolic volume. Rats treated with alamandine had reduced E/E' ratio (15.16 ± 1.04* vs 26.81 ± 3.79) and increased E'/A' ratio (1.09 ± 0.05 vs 0.57 ± 0.07 ** P<0.01), indicating the improved diastolic cardiac function. The reduced myocardial performance index (0.74 ± 0.06* vs. 1.24 ± 0.15) in alamandine treated rats demonstrated an improvement of global cardiac dysfunction. Histological analysis also revealed that alamandine attenuated ISO induced increase in cardiomyocyte size (372.46 ± 11.13** vs 551.99 ± 11.79 μm 2 ) and myocardial fibrosis (1.39 ± 0.16 ** vs 4.57 ± 0.35), along with reduced mRNA expression of hypertrophy biomarkers atrial natriuretic peptide (2.45 ± 0.71** vs 8.08 ± 0.74), brain natriuretic peptide (2.86 ± 0.35 ** vs 12.53 ± 1.12), beta myosin heavy chain (1.71 ± 0.25* vs 5.38 ± 0.95) and fibrosis genes – collagen-1 (1.97 ± 0.45* vs 4.25 ± 0.6), fibronectin (2.04 ± 0.32** vs 5.05 ± 0.74), α-smooth muscle actin (1.53 ± 0.1** vs 2.71 ± 0.17). Flow cytometry analysis unveiled that alamandine reduced neutrophil, CD8 T cells and M1 monocytes, but increased M2 monocytes of left ventricle, implying the reduction of inflammation of the heart. These data suggest that alamandine plays a cardioprotective role in improving cardiac hypertrophy and fibrosis, probably via an immune mechanism to alleviate inflammatory responses during cardiac remodeling.

In recent years, locust plagues have occurred frequently in the world, causing great concern. In this work, we developed a portable, stand-alone functional nucleic acid sensor to detect the locust pheromone 4-vinylanisole (4VA) to monitor the population dynamics of locusts and achieve early warning of locust disasters. A high-affinity aptamer sequence with a 4VA KD value of 269.25 +/- 90.65 nM was obtained by selecting the 4VA DNA aptamer. The Apt@AuNPs@MOF (Apt: aptamer, AuNPs: gold nanoparticles, and MOF: metal-organic framework) functional nucleic acid sensor was designed on this basis, and its performance was tested. The results showed that the sensor based on the screened DNA aptamers had apparent selectivity for 4VA. At room tem-perature, it could respond to 1 ppm of 4VA gas within a minute. The sensitivity was 1.107 x 10-3, and the average response/recovery time was 103.1 +/- 28.0 s/80.1 +/- 17.4 s. The sensor was assembled with a composite adsorption tube for enrichment of gas sample, which allowed for the detection as low as 1 ppb of 4VA. It can be concluded that a gas sensor integrated with a high-affinity DNA aptamer and an interdigitated electrode auto-mated biosensing platform provides a promising strategy on real-time monitoring the locust pheromone 4VA in ambient air for timely warning and prevention of locust plagues.

Interleukin (IL)-17A, a key inflammatory mediator produced primarily by T helper (Th) 17 cells, has been implicated in the pathogenesis of cardiovascular diseases including hypertension and heart failure. IL-17A can access the brain by disrupting blood-brain barrier (BBB) integrity to induce neuroinflammation. We previously reported that IL-17A contributes to angiotensin (ANG) II-induced hypertension via promoting neuroinflammation and sympathetic excitation. The nuclear receptor retinoid-related orphan receptor γt (RORγt) is a master transcription factor regulating Th17 cell differentiation. Here, we sought to determine whether systemic inhibition of RORγt attenuates IL-17A production and diminishes ANG II-induced neuroinflammation and hypertension. Sprague-Dawley rats received a 2-week subcutaneous (sc) infusion of ANG II (150 ng/kg/min) combined with daily sc injection of a RORγt inhibitor digoxin or vehicle (VEH). Compared with the control animals, blood pressure (162±5* vs 118±3 mmHg, *P<0.05) and sympathetic tone as indicated by blood pressure change in response to ganglionic blockade (55±5* vs 23±3 mmHg) were increased in ANG II+VEH rats, which were reduced (38-41%*) in ANG II+digoxin rats. ANG II+VEH rats also had elevated RORγt mRNA in peripheral blood mononuclear cells (PBMCs: 3.38±0.70* vs 1.12±0.22) and higher IL-17A levels in plasma (23.22±5.85 * vs 4.30±0.66 pg/mL), along with increased IL-17A levels in cerebrospinal fluid (CSF: 11.89±1.91* vs 2.01±0.55 pg/mL), mRNA of IL-17A (3.02±0.48* vs 1.07±0.17), cytokines tumor necrosis factor (TNF)-α (2.78±0.45* vs 1.04±0.12) and IL-1β (2.57±0.53* vs 1.03±0.14) in the hypothalamic paraventricular nucleus (PVN), a key cardiovascular-related center in the brain. Although RORγt mRNA was unchanged in PBMCs, levels of IL-17A in plasma and CSF, mRNA of IL-17A, TNF-α and IL-1β in the PVN was reduced (41-62 %*) in ANG II+digoxin rats. Additionally, mRNA of caveolin-1 (2.26±0.39* vs 1.06±0.17), a marker of the BBB permeability, was increased in the PVN in ANG II+VEH rats and decreased (43%*) in ANG II+digoxin rats. These data suggest that RORγt inhibition improves ANG II-induced hypertension and sympathetic activation probably by reducing IL-17A production and neuroinflammation.

Cerebral ischemic injury is an important factor affecting the prognosis of acute ischemic stroke (AIS). Neuronal apoptosis and the change in microglial phenotype have been implicated in the development of AIS. The changes in microglia from the M1 phenotype to the M2 phenotype could rescue neurons and reduce apoptosis. MiRNA-Let-7c reduced ischemic injury by regulating the survival of neurons and changing microglial phenotype. Here, we used the information regarding the changes in the brain microenvironment after ischemic injury and constructed pH-sensitive polymeric nanoparticles to deliver miRNA-Let-7c. The nanoparticles were coated with platelet membrane, which preserved the function of platelets while allowing nanoparticles to evade recognition by the immune system. The platelet membrane-camouflaged nanoparticles entered the neutrophils by endocytosis and used inflammatory chemotaxis of neutrophils to transport the vector across the blood-brain barrier (BBB). The platelet membrane-camouflaged nanoparticles efficiently localized to the area of the ischemic injury and delivered the miRNA-Let-7c for the targeted regulation of neurons and microglia. Based on these results, we conclude that this strategy is a favorable gene delivery system and could effectively treat ischemic injury. (C) 2022 Elsevier Ltd. All rights reserved.

The complement system plays an important role in host innate immunity, and its activation can be exploited as a potential strategy for vaccine adjuvants. Herein, a pH-responsive micellar vaccine platform (COOH-NPs) was developed using a carboxyl-modified diblock copolymer of poly(2-ethyl-2-oxazoline)-poly(d,l-lactide) (COOH-PEOz-PLA). The copolymer self-assembled into micelles with hydroxyl groups shielding on the surface, which activated the complement system for the enhanced immune responses. Compared with the control nanoparticles (OCH3-NPs), COOH-NPs significantly enhanced lymph node-resident dendritic cell maturation, antigen-specific IgG production, antigen-specific CD4+ and CD8+ T-cell activation, and the amount of memory T-cell generation in vivo. Furthermore, immunization with COOH-NPs/OVA in E.G7-OVA tumor-bearing mice not only remarkably inhibited tumor growth but also prolonged the survival of tumor-bearing mice. These results indicated that COOH-NPs with the capability of complement activation efficiently boosted the immune responses for the antitumor effect. The study demonstrated the significance of taking advantage of a complement-activating vaccine platform for cancer immunotherapy.

Aim: To develop a nanocarrier for targeted delivery of agents to the cartilage. Materials & methods: Chondrocyte affinity peptide modified PEGylated polyamidoamine conjugates (CAP-PEG-PAMAM) were prepared and rhodamine B isothiocyanate (RB) fluorophore was linked on them for comparative biological tracing and profiling. Results: CAP4-PP-RB exhibited much more efficient cellular uptake in vitro than that of PEG-PAMAM-RB. Both the conjugates were likely internalized by chondrocytes via clathrin and caveolin co-mediated endocytosis, and delivered to lysosomes. In vivo imaging demonstrated the fluorescein-labeled nanocarrier was capable to persist in the joint cavity of rats for a prolonged time. Furthermore, the CAP4-PEG-PAMAM showed a good biocompatibility and enhanced penetration effects in vivo. Conclusion: CAP-PEG-PAMAM could be an effective nanocarrier for intra-articular delivery of agents to cartilage.

It has been widely accepted that lymph nodes (LNs) are critical targets of cancer vaccines because antigen presentation and initiation of T-cell-mediated immune responses occur primarily at these locations. In this study, amphiphilic diblock copolymer poly(2-ethyl-2-oxazoline)-poly(d,l-lactide) (PEOz-PLA) combined with carboxylterminated-Pluronic F127 was used to construct mixed micelles [carboxylated-nanoparticles (NPs)] for codelivery of antigen ovalbumin (OVA) and Toll-like receptor-7 agonist CL264 (carboxylated-NPs/OVA/CL264) to the LN-resident dendritic cells (DCs). The results showed that the small, sub-60 nm size of the self-assembled mixed micelles enables them to rapidly penetrate into lymphatic vessels and reach draining lymph nodes after subcutaneous injection. Furthermore, the surface modification with carboxylic groups imparted the carboxylated-NPs with endocytic receptor-targeting ability, allowing for DC internalization of carboxylated-NPs/OVA/CL264 via the scavenger receptor-mediated pathway. Because stimulation of CL264 in early endosomes will lead to a more effective immune response than that in late endo/lysosomes, the mass ratio of PEOz-PLA to carboxylated-Pluronic F127 in the mixed micelles was adjusted to release the encapsulated CL264 to the early endosome, resulting in increased expression of costimulatory molecules and secretion of stimulated cytokines by DCs. Moreover, the incorporation of PEOz outside the micellar shell effectively augmented MHC I antigen presentation through facilitating endosome escape and cytosolic release of antigens. This in turn evoked potent immune responses in vivo, including activation of antigen-specific T-cell responses, production of antigen-specific IgG antibodies, and generation of cytotoxic T-lymphocyte responses. Finally, immunization with the codelivery system in E.G7-OVA tumor-bearing mice could not only significantly inhibit tumor growth but also markedly prolong the survival of tumor-bearing mice. Taken together, carboxylated-NPs/OVA/CL264 have demonstrated great potential for clinical applications as an effective antitumor vaccine for further immunotherapy.

In the present report, a degradable gene delivery system (PAMS/DNA/1 0NLS) containing nucleus location signal peptide (NLS) was prepared. The agarose gel electrophoresis, particle size and zeta potential of PAMS/DNA/10NLS were similar to those of PAMS/DNA, which proved that NLS did not affect the interaction between PAMS and DNA. PAMS/DNA/10NLS exhibited marked extracellular and intracellular degradation under acidic conditions. The degradation was believed to allow NLS to come into contact with importins easily, which was able to mediate the nucleus import. With the help of NLS, PAMS/ DNA/10NLS exhibited a higher transfection capability than PAMS/DNA. Moreover, the transfection of PAMS/DNA/10NLS was less dependent on the breakdown of the nucleus envelope than PAMS/DNA. Considering that GTPase-activating protein 1 (RanGAP1) was able to activate the endogenous GTPase, which was necessary for NLS-mediated nucleus import, RanGAP1 overexpressed cells (RanGAP1 cells) were produced. This result showed that RanGAP1 cells had higher GTPase activities than normal cells. Both the nucleus import and transfection efficiency of PAMS/DNA/10NLS were markedly higher in RanGAP1 cells than that in normal cells. The in vivo transfection results also showed that the transfection efficiency of PAMS/DNA/10NLS was higher in RanGAP1 pre-treated mice than that in normal mice. These findings showed that PAMS/DNA/10NLS is a promising gene delivery system with the assistance of RanGAP1. Statement of Significance The present report describes the increased transfection efficiency of a degradable gene delivery system (PAMS/DNA/10NLS) containing nuclear location signal (NLS) with the assistance of GTPase-activating protein 1 (RanGAP1). The physicochemical properties of PAMS/DNA/10NLS were similar to those of PAMS/DNA. PAMS/DNA/10NLS exhibited great extracellular and intracellular degradations, which might allow NLS to contact with importins easily. With the help of NLS, PAMS/DNA/10NLS exhibited a higher transfection capability than PAMS/DNA. The transfection of PAMS/DNA/10NLS had less dependence on the breakdown of nuclear envelope. Both the nuclear import and transfection efficiency of PAMS/ DNA/10NLS were higher in RanGAP1 overexpressed cells than that in normal cells. Moreover, the transfection efficiency of PAMS/DNA/lONLS was higher in RanGAP1 pre-treated mice than that in normal mice. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Various biotin-modified liposomes incorporated with docetaxel (DTX) were prepared to study the effect of surface biotin density on the pharmacokinetic profile of the liposome. Four types of liposomes such as PEG modified liposome (PDL), 0.5% (mol) biotin modified liposome (0.5BDL), 1% (mol) biotin modified liposome (1BDL) and 2% (mol) biotin modified liposome (2BDL) were prepared using thin film dispersion method. The prepared liposomes were characterized by measuring encapsulation efficiency (EE), particle size, Zeta-potential, physical stability and drug release profiles in vitro. MTT assay was performed to elevate the cytotoxicity of liposomes on MCF-7 cells. In vivo evaluation was further performed to investigate the effect of biotin surface density on the pharmacokinetic profiles. All the prepared liposomes exhibited high encapsulation efficiency, small particle size, narrow particle distribution and sustained release profiles in vitro. In MTT assay, 0.5BDL showed largest tumor cell toxicity, compared with DTX solution. All liposomes containing DTX showed prolonged blood circulation in vivo, and 0.5BDL showed the longest circulation time among the biotin modified liposome. Surface modification of liposome had a negative impact on the circulation of liposomes in the blood, which needs to be considered when designing the ligand mediated targeting delivery systems. A proper amount of biotin liposome with 0.5% molar ratio is expected to produce the best anti-tumor effect.

A novel pH-sensitive conjugate glycyrrhetinic acid–polyethylene glycol–Schiff bond–cholesterol (GPSC) has been synthesized successfully and used to construct doxorubicin-loaded liposomes with both pH-sensitive features and active targeting ability.

Multidrug resistance (MDR) of tumor cells is becoming the main reason for the failure of chemotherapy and P-glycoprotein (P-gp) mediated drug efflux has demonstrated to be the key factor for MDR. To address this issue, a novel pH-responsive mixed micelles drug delivery system composed of dextran-gpoly(lactide-co-glycolide)-g-histidine (HDP) and folate acid-D-alpha-tocopheryl polyethylene glycol 2000 (FA-TPGS2K) copolymers has been designed for the delivery of antitumor agent, paclitaxel (PTX) via FA-receptor mediated cell endocytosis, into PTX-resistant breast cancer MCF-7 cells (MCF-7/PTX). PTXloaded FA-TPGS2K/HDP mixed micelles were characterized to have a small size distribution, high loading content and excellent pH-responsive drug release profiles. Compared with HDP micelles, FA-TPGS2K/HDP mixed micelles showed a higher cytotoxicity against MCF-7 and MCF-7/PTX cells due to the synergistic effect of FA-receptor mediated cell endocytosis, pH-responsive drug release and TPGS mediated P-gp inhibition. P-gp expression level, ATP content and mitochondrial membrane potential change have been measured, the results indicated blank FA-TPGS2K/HDP mixed micelles could inhibit the P-gp activity by reducing the mitochondrial membrane potential and depleting ATP content but not down-regulating the P-gp expression. In vivo antitumor activities demonstrated FA-TPGS2K/HDP mixed micelles could reach higher antitumor activity compared with HDP micelles for MCF-7/PTX tumor cells. Histological assay also indicated that FA-TPGS2K/HDP mixed micelles showed strongly apoptosis inducing effect, anti proliferation effect and anti-angiogenesis effect. All these evidences demonstrated this pH-sensitive FA-TPGS2K/HDP micelle-based drug delivery system is a promising approach for overcoming MDR.Statement of SignificanceIn this work, a novel FA-TPGS2K copolymer has been synthesized and used it to construct mixed micelles with HDP copolymer to overcome MDR effect. Furthermore, a series in vitro and in vivo evaluations have been made, which supported enough evidences for the efficient delivery of antitumor drug to MDR cells. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

The present report describes the synthesis of a hydroxyl terminal PAMAM dendrimer (PAMAM-OH) derivative (PAMSPF). The hydroxyls of PAMAM-OH were attached to S-Methyl-l-cysteine (SMLC) via an acid-labile ester bond, named as β-thiopropionate bond, followed by modification with folic acid (FA) through a polyethylene glycol (PEG) linker. The degrees of attachment of SMLC and FA to the PAMAM-OH backbone were 83.9% and 12.8%, respectively. PAMSPF could condense DNA to form spherical nanoparticles with particle sizes of ∼200nm and remain stable in the presence of heparin and nuclease. The β-thiopropionate bond in PAMSPF was hydrolyzed completely and the DNA release rate was 95.8±3.3% after incubation under mildly acidic conditions at 37°C for 3h. PAMSPF/DNA was less cytotoxic to KB and HepG2 cells and exhibited a higher gene transfection efficiency than native PAMAM/DNA. The uptake assays showed that PAMSPF/DNA entered KB cells within 0.5h through folate receptor-mediated endocytosis and escaped from endosomes within 2h. In addition, PAMSPF/DNA displayed long circulation time along with excellent targeting of tumor sites in vivo. These findings demonstrate that PAMSPF is an excellent carrier for safe and effective gene delivery.

Background The purpose of this study was to construct hollow mesoporous silica nanoparticles (HMSN) decorated with tLyp-1 peptide (tHMSN) for dual-targeting drug delivery to tumor cells and angiogenic blood vessel cells. Methods HMSN were synthesized de novo using a novel cationic surfactant-assisted selective etching strategy and were then modified with tLyp-1. Multiple methods, including transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, bicinchoninic acid assay, and nitrogen adsorption and desorption isotherms, were used to characterize the tHMSN. Doxorubicin were chosen as the model cargo, and the uptake of doxorubicin-loaded tHMSN into MDA-MB-231 cells and human umbilical vein endothelial cells (HUVECs), as models of tumor cells and tumor neovascular endothelial cells, respectively, were observed and detected by confocal laser scanning microscopy and flow cytometry. An in vitro pharmacodynamic study and a study of the mechanism via which the nanoparticles were endocytosed were also performed. Results HMSN with a highly uniform size and well oriented mesopores were synthesized. After tHMSN were characterized, enhanced uptake of the cargo carried by tHMSN into MDA-MB-231 cells and HUVECs compared with that of their unmodified counterparts was validated by confocal laser scanning microscopy and flow cytometry at the qualitative and quantitative levels, respectively. Further, the pharmacodynamic study suggested that, compared with their unmodified counterparts, doxorubicin-loaded tHMSN had an enhanced inhibitory effect on MDA-MB-231 cells and HUVECs in vitro. Finally, a preliminary study on the mechanism by which the nanoparticles were endocytosed indicated that the clathrin-mediated endocytosis pathway has a primary role in the transport of tHMSN into the cytoplasm. Conclusion tHMSN might serve as an effective active targeting nanocarrier strategy for anti-mammary cancer drug delivery.

Stimuli-responsive nanocarriers attract wide attention because of the unique differences in microenvironment between solid tumors and normal tissues. Herein, we reported a novel cRGDyK peptide modified pH-sensitive nanoparticle system based on poly(ethylene glycol)-poly(2,4,6-trimethoxy benzylidene-pentaerythritol carbonate) (PEG-PTMBPEC) diblock copolymer, which was expected to destroy tumor angiogenesis and kill tumor cells simultaneously. Doxorubicin (DOX)-loaded nanoparticles (NPs) were characterized to have a uniform size distribution, high entrapment efficiency, good stability in plasma as well as a pH dependent drug release pattern. Blank NPs were non-toxic to both tumor cells and normal cells, while DOX-loaded cRGDyK peptide modified NPs (cRGDyK-NPs) exhibited the pronounced cytotoxicity against B16 cells and human umbilical vein endothelial cells (HUVEC) overexpressing alpha(v)beta(3) integrin receptors. Cellular uptake studies revealed that the highly efficient uptake of cRGDyK-NPs was attributed to the receptor-mediated endocytosis and acidic-triggered drug release. Importantly, cRGDyK-NPs could dramatically reduce the systemic toxicity of DOX and exert excellent tumor killing activity in vivo. The cRGDyK modified pH-sensitive nanocarrier is a promising vehicle for intracellular drug delivery to alpha(v)beta(3) integrin receptor overexpressed tumor cells and neovascular cells.Statement of SignificanceSlow intracellular drug release and poor tumor targeting capacity are still the critical barriers of polymeric nanoparticles (NPs) for the treatment efficiency of chemotherapy. In the present study, we designed cRGDyK peptide modified poly(ethylene glycol)-poly(2,4,6-trimethoxybenzylidene-pentaery thritol carbonate) (cRGDyK-PEG-PTMBPEC) NPs with active targeting and fast pH-triggered drug release. Doxorubicin (DOX)-loaded cRGDyK-PEG-PTMBPEC NPs exhibited pronounced cytotoxicity and enhanced cellular uptake against B16 cells and human umbilical vein endothelial cells overexpressing alpha v beta 3 integrin receptors. Moreover, the active targeted pH-sensitive NPs can enhance the antitumor activity and reduce the systematic toxicity of DOX in vivo. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Photothermal therapy (PTT) is widely regarded as a promising technology for cancer treatment. Gold nanorods (GNRs), as excellent PTT agent candidates, have shown high-performance photothermal conversion ability under laser irradiation, yet two major obstacles to their clinical application are the lack of selective accumulation in the target site following systemic administration and the greatly reduced photothermal conversion efficiency caused by self-aggregating in aqueous environment. Herein, we demonstrate that tLyp-1 peptide-functionalized, indocyanine green (ICG)-containing mesoporous silica-coated GNRs (I-TMSG) possessed dual-function as tumor cells-targeting near-infrared (NIR) fluorescent probe and PTT agents. The construction of the nanostructure began with synthesis of GNRs by seed-mediated growth method, followed by the coating of mesoporous silica, the chemical conjugation of PEG and tLyp-1 peptide, and the enclosure of ICG as an NIR imaging agent in the mesoporous. The as-prepared nanoparticles could shield the GNRs against their self-aggregation, improve the stability of ICG, and exhibit negligible dark cytotoxicity. More importantly, such a theranostic nanocomposite could realize the combination of GNRs-based photothermal ablation under NIR illumination, ICG-mediated fluorescent imaging, and tLyp-1-enabled more easy endocytosis into breast cancer cells. All in all, I-TMSG nanoparticles, in our opinion, possessed the strong potential to realize the effective diagnosis and PTT treatment of human mammary cancer.

A novel pH-sensitive polymer, poly(l-histidine)–poly(lactide-co-glycolide)–tocopheryl polyethylene glycol succinate (PLH–PLGA–TPGS), was synthesized to design a biocompatible drug delivery system for cancer chemotherapy. The structure of the PLH–PLGA–TPGS copolymer was confirmed by 1H-NMR, FTIR and GPC. The apparent pKa of the PLH–PLGA–TPGS copolymer was calculated to be 6.33 according to the acid–base titration curve. The doxorubicin (DOX)-loaded nanoparticles (PLH–PLGA–TPGS nanoparticles and PLGA–TPGS nanoparticles) and corresponding blank nanoparticles were prepared by a co-solvent evaporation method. The blank PLH–PLGA–TPGS nanoparticles showed an acidic pH-induced increase in particle size. The DOX-loaded nanoparticles based on PLH–PLGA–TPGS showed a pH-triggered drug-release behavior under acidic conditions. The results of in vitro cytotoxicity experiment on MCF-7 and MCF-7/ADR cells showed that the DOX-loaded PLH–PLGA–TPGS nanoparticles resulted in lower cell viability versus the PLGA–TPGS nanoparticles and free DOX solution. Confocal laser scanning microscopy images showed that DOX-loaded PLH–PLGA–TPGS nanoparticles were internalized by MCF-7/ADR cells after 1 and 4 h incubation and most of them accumulated in lysosomes to accelerate DOX release under acidic conditions. In summary, the PLH–PLGA–TPGS nanoparticles have great potential to be used as carriers for anti-tumor drug delivery.