UNASSIGNED: Flurbiprofen axetil (FA) is a non-steroidal anti-inflammatory drug with good analgesic and anti-inflammatory effects. However, it suffers from poor solubility, short circulation time, and off-target binding profile, which significantly limit its clinical application. Here, we loaded FA into stealth lipid microspheres modified with the arginine-glycine-aspartic acid (RGD) peptide (cRGD-FA-SLM), and examined the therapeutic potential of the resulting platform for the treatment of rheumatoid arthritis (RA).
UNASSIGNED: cRGD-FA-SLM was prepared by high pressure homogenization, and its toxicity and uptake by macrophages were examined using cultures of RAW264.7 cells. Hemolysis and hepatotoxicity tests were performed to assess the safety of the developed platform, while its pharmacokinetics, biodistribution, and therapeutic efficacy were investigated in a collagen-induced arthritis rat model.
UNASSIGNED: cRGD-FA-SLM showed homogeneous spherical morphology and efficient encapsulation of FA. The developed platform was non-toxic to normal macrophages and was selectively internalized by lipopolysaccharide-activated macrophages in vitro, while it distributed mainly to arthritic joints and significantly prolonged FA in circulation in vivo. cRGD-FA-SLM also significantly reduced the expression of prostaglandin E2 and alleviated joint edema and bone erosion, showing prolonged analgesic effects in arthritic rats.
UNASSIGNED: cRGD-FA-SLM shows good inflammation-targeting ability and prolongs drug circulation in vivo, suggesting promise as an anti-inflammatory and analgesic agent for targeted RA treatment.

Breast cancer is the most common malignant tumor in women and is a big challenge to clinical treatment due to the high morbidity and mortality. The pH/ROS dual-responsive nanoplatforms may be an effective way to significantly improve the therapeutic efficacy of breast cancer. Herein, we report a docetaxel (DTX)-loaded pH/ROS-responsive NP that could achieve active targeting of cancer cells and selective and complete drug release for effective drug delivery. The pH/ROS-responsive NPs were fabricated using nanocarriers that consist of an ROS-responsive moiety (4-hydroxymethylphenylboronic acid pinacol ester, HPAP), cinnamaldehyde (CA, an aldehyde organic compound with anticancer activities) and cyclodextrin (α-CD). The NPs were loaded with DTX, modified with a tumor-penetration peptide (circular RGD, cRGD) and named DTX/RGD NPs. The cRGD could promote DTX/RGD NPs penetration into deep tumor tissue and specifically target cancer cells. After internalization by cancer cells through receptor-mediated endocytosis, the pH-responsive acetal was cleaved to release CA in the lysosomal acidic environment. Meanwhile, the high ROS in tumor cells induced the disassembly of NPs with complete release of DTX. In vitro cellular assays verified that DTX/RGD NPs could be effectively internalized by 4T1 cells, obviously inducing apoptosis, blocking the cell cycle of 4T1 cells and consequently, killing tumor cells. In vivo animal experiments demonstrated that the NPs could target to the tumor sites and significantly inhibit the tumor growth in 4T1 breast cancer mice. Both in vitro and in vivo investigations demonstrated that DTX/RGD NPs could significantly improve the antitumor effect compared to free DTX. Thus, the DTX/RGD NPs provide a promising strategy for enhancing drug delivery and cancer therapy.

Astrocytes play an important role in the central nervous system, contributing to the development of and maintenance of synapses, recycling of neurotransmitters, and the integrity and function of the blood-brain barrier. Astrocytes are also linked to the pathophysiology of various neurodegenerative diseases. Astrocyte function and organization are tightly regulated by interactions mediated by the extracellular matrix (ECM). Engineered hydrogels can mimic key aspects of the ECM and can allow for systematic studies of ECM-related factors that govern astrocyte behaviour. In this study, we explore the interactions between neuroblastoma (SH-SY5Y) and glioblastoma (U87) cell lines and human fetal primary astrocytes (FPA) with a modular hyaluronan-based hydrogel system. Morphological analysis reveals that FPA have a higher degree of interactions with the hyaluronan-based gels compared to the cell lines. This interaction is enhanced by conjugation of cell-adhesion peptides (cRGD and IKVAV) to the hyaluronan backbone. These effects are retained and pronounced in 3D bioprinted structures. Bioprinted FPA using cRGD functionalized hyaluronan show extensive and defined protrusions and multiple connections between neighboring cells. Possibilities to tailor and optimize astrocyte-compatible ECM-mimicking hydrogels that can be processed by means of additive biofabrication can facilitate the development of advanced tissue and disease models of the central nervous system.

BACKGROUND: Melanoma is the most malignant skin tumor and is difficult to cure with the alternative treatments of chemotherapy, biotherapy, and immunotherapy. Our previous study showed that triptolide (TP) exhibited powerful tumoricidal activity against melanoma. However, the clinical potential of TP is plagued by its poor aqueous solubility, short half-life, and biotoxicity. Therefore, developing an ideal vehicle to efficiently load TP and achieving targeted delivery to melanoma is a prospective approach for making full use of its antitumor efficacy.
RESULTS: We applied exosome (Exo) derived from human umbilical cord mesenchymal stromal cells (hUCMSCs) and engineered them exogenously with a cyclic peptide, arginine-glycine-aspartate (cRGD), to encapsulate TP to establish a bionic-targeted drug delivery system (cRGD-Exo/TP), achieving synergism and toxicity reduction. The average size of cRGD-Exo/TP was 157.34 ± 6.21 nm, with a high drug loading of 10.76 ± 1.21%. The in vitro antitumor results showed that the designed Exo delivery platform could be effectively taken up by targeted cells and performed significantly in antiproliferation, anti-invasion, and proapoptotic activities in A375 cells via the caspase cascade and mitochondrial pathways and cell cycle alteration. Furthermore, the biodistribution and pharmacokinetics results demonstrated that cRGD-Exo/TP possessed superior tumor targetability and prolonged the half-life of TP. Notably, cRGD-Exo/TP significantly inhibited tumor growth and extended survival time with negligible systemic toxicity in tumor-bearing mice.
CONCLUSIONS: The results indicated that the functionalized Exo platform provides a promising strategy for targeted therapy of malignant melanoma.

To improve the bioavailability of hydrophobic drugs and realize tumor targeting therapeutic actions efficiently, a nanosized multifunctional protein-based drug delivery system was constructed by self-assembly in a facile manner. Negatively charged cRGD-conjugated bovine serum albumin (cRGD-BSA) loaded with a hydrophobic antitumor drug (curcumin, CUR) was complexed with electropositive protamine sulfate (PS) via electroattractive forces to form CUR@cRGD-BSA/PS nanoparticles. Flow cytometry and confocal microscopy show that the multifunctional CUR@cRGD-BSA/PS nanoparticles lead to significantly increased intracellular drug accumulation in tumor cells owing to the tumor specific affinity of cRGD ligands as well as the membrane translocating property of PS. As a result, the multifunctional protein-based delivery system (CUR@cRGD-BSA/PS) exhibits an apparently enhanced inhibitory efficiency on malignant cells as compared with free CUR and the monofunctional delivery system (CUR@cRGD-BSA). More importantly, the expression of proteins (Bcl-2, cyclin D1, β-catenin, c-Myc, and MMP-9) involved in cancer development in the tumor cells treated by CUR@cRGD-BSA/PS is dramatically downregulated, implying the functional protein-based drug delivery system can effectively prevent tumor progression. Our investigation gives insight into the construction of multifunctional protein-based delivery carriers for tumor targeting delivery of hydrophobic drugs.

Despite the success of small interfering RNAs (siRNAs) in clinical settings, their fast clearance and poor delivery efficiency to target cells still hinder their therapeutic effect. Herein, a new treatment system was constructed by combining thermosensitive liposomes with the macrophage membrane, tumor-targeting cyclic Arg-Gly-Asp peptide, a cell-penetrating peptide, and thermotherapy. The constructed system was found to be thermosensitive and stable; the proteins were inherited from the macrophage membrane. This new system combined with thermotherapy displayed the least uptake by macrophages, the greatest uptake by HepG2 cells, the most obvious HepG2 cell apoptosis, and the strongest inhibition of Bcl-2 mRNA and Bcl-2 protein in HepG2 cells. Moreover, 24 h after system administration in tumor-bearing mice, the most prominent distribution of siRNA was observed in tumors, while almost no siRNA was found in other organs. The strongest inhibition of Bcl-2 mRNA, Bcl-2 protein, and tumors was found in mice that had received the proposed system. In summary, when using the constructed system both in vitro and in mice, less uptake by the reticuloendothelial system, greater accumulation in tumor cells, and improved therapeutic efficacy were observed. Therefore, this new system can deliver siRNA selectively and efficiently, and it is a promising therapeutic candidate for precise tumor-targeted therapy.

Traditional combined photodynamic and photothermal therapy (PDT/PTT) was limited in clinical treatment of cancer due to the exceptionally low drug delivery efficiency to tumor sites and the activation by laser excitation with different wavelengths. We have accidentally discovered that our synthesized chlorin e6-C-15-ethyl ester (HB, a new type of photosensitizer) be activated by a laser with an excitation wavelength of 660 nm. Herein, we utilized Au nanorods (AuNRs) as 660 nm-activated PTT carriers to be successively surface-functionalized with HB and tumor-targeting peptide cyclic RGD (cRGD) to develop HB-AuNRs@cRGD for single NIR laser-induced targeted PDT/PTT. The HB-AuNRs@cRGD could be preferentially accumulated within tumor sites and rapidly internalized by cancer cells. Thereby, the HB-AuNRs@cRGD could exhibit amplified therapeutic effects by producing both significant reactive oxygen species (ROS) and hyperthermia simultaneously under the guidance of fluorescence imaging. The tumor inhibition rate on ECA109 esophageal cancer model was approximately 77.04%, and the negligible systematic toxicity was observed. This study proposed that HB-AuNRs@cRGD might be a promising strategy for single NIR laser-induced and imaging-guided targeted bimodal phototherapy.

Poor safety and effectiveness is an outstanding challenge in the preparation of drug delivery systems (DDS) for cancer treatment. The pursuit of the high curative effect will inevitably increase the risk of adverse side effects. Herein, a bio-safe DDS was constructed by combining the advantages of functional zein and Au doped mesoporous silica nanoparticles (Au@SiO2) to achieve chemo-photothermal therapy. The cRGD functionalized zein (cRGD-Zein) was coated on the surface of Au@SiO2 which effectively avoided premature leakage of paclitaxel and realized sustained drug release. Meanwhile, the high hemolysis rate (107%) of Au@SiO2 had been significantly reduced to 4%. The anti-hemolysis mechanism of functionalized zein was explored to give a deeper understanding of the interaction between nanoparticles and RBCs. The results showed that the functional zein would change the protein conformation during the interaction with Au@SiO2 to protect the RBCs from the damage of Au@SiO2. And the release rate of hemoglobin was limited by the size of RBCs membrane cracks with approximately 40 nm in width and 470 nm in length. The cell cytotoxicity and uptake assays showed that the prepared DDS exhibited low tumour cell viability (35%) and enhanced uptake performance (99.3%). This work suggested that the prepared nanoparticles could serve as a promising carrier to achieve safe and efficacious tumour therapy.

UNASSIGNED: Atherosclerosis (AS) is one of the main causes of cardiovascular disease which might lead to myocardial infarction or stroke and further leads to fatality.
UNASSIGNED: In this study, we have designed an anti-inflammatory cytokine interleukin-10 (IL10) delivery system to effectively alleviate the inflammation of atherosclerosis plaque. The targeted delivery of IL10 to the atherosclerotic plaques was achieved by cRGD conjugated liposomes (IL10-cRGD-Lip).
UNASSIGNED: The IL10-cRGD-Lip of size 179.4 ± 10.91 nm having PDI 0.14 ± 0.04 with a surface charge of +18.34 ± 1.36 mV was prepared. The in-vitro analysis clearly suggests that IL10-cRGD-Lip sustains the release of IL10 and could significantly reduce ROS and NO. The immuno-staining results revealed that IL-1β and TNF-α were down-regulated after the treatment with IL10-cRGD-Lip in Lipopolysaccharide (LPS) stimulated RAW 264.7 cells.
UNASSIGNED: the in-vitro results clearly suggest that anti-inflammatory cytokine IL10 could be used for the cure of inflammatory maladies including atherosclerosis.

To improve antitumor efficiency of chemotherapy and reduce side effect, according to the physiological characteristics of tumor tissues and tumor intracellular microenvironment, a multifunctional drug delivery system with properties of long circulation, active targeting, redox and pH triggered drug release was established based on the Generation 4 polyamidoamine dendrimer (PAMAM). First, the redox cleavable disulfide bonds (SS) were introduced for linking polyethylene glycol (PEG) with PAMAM to form PAMAM-S-S-PEG (PSSP). Then cRGD peptide was applied to the PEG end of PSSP to construct RGD-PSSP conjugates. Finally, encapsulating the antitumor chemotherapy drug doxorubicin (DOX) into the hydrophobic cavity of RGD-PSSP conjugates constructed the RGD-PSSP/DOX drug delivery system. The in vitro experiments displayed that RGD-PSSP/DOX NPs showed obviously redox and pH dual sensitive drug release profile. MTT and cell uptake observation elucidated cRGD modification could increase the cytotoxicity, and promote the uptake of B16 cells and HUVEC cells both overexpressing integrin ανβ3on cell membrane. Cell uptake mechanism investigation further revealed that RGD-PSSP/DOX interacted with plasma membrane via specific recognition of cRGD peptide with integrin ανβ3, and was subsequently internalized mainly through clathrin- and caveolin-mediated endocytosis. Remarkably, RGD-PSSP/DOX presented superior anticancer activity and lower heart and kidney toxicity in vivo, which could be regarded as a potential candidate for efficient antitumor chemotherapy drug delivery.