All-stage targeted red blood cell membrane-coated docetaxel nanocrystals for glioma treatment.

Challenges for glioma treatment with nanomedicines include physio-anatomical barriers (the blood-brain barrier and blood-brain tumor barrier), low drug loading capacity, and limited circulation time. Here, a red blood cell membrane-coated docetaxel drug nanocrystal (pV-RBCm-NC(DTX)), modified with pHA-VAP (pV) for all-stage targeting of glioma, was designed. The NC(DTX) core exhibited a high drug loading capacity but low in vivo stability, and the RBCm coating significantly enhanced the stability and prolonged in vivo circulation. Moreover, the Y-shaped targeting ligand pV was modified by a mild avidin-biotin interaction, which endowed RBCm-NC(DTX) with superior barrier-crossing ability and therapeutic efficacy. The integration of nanocrystal technology, cell membrane coating, and the avidin-biotin insertion method into this active targeting biomimetic formulation represents a promising drug delivery strategy for glioma.

A pentapeptide enabled AL3810 liposome-based glioma-targeted therapy with immune opsonic effect attenuated.

AL3810, a molecular dual inhibitor of the vascular endothelial growth factor receptor (VEGFR) and fibroblast growth factor receptor (FGFR), has earned the permission of phase II clinical trial for tumor treatment by China FDA. As a reversible ATP-competitive inhibitor, AL3810 targets ATP-binding site on intracellular region of VEGFR and FGFR, whereas, AL3810 lacking interplay with extracellular region of receptors rendered deficient blood-brain tumor barrier (BBTB) recognition, poor brain penetration and unsatisfactory anti-glioma efficacy. Integrin αvß3 overexpressed on capillary endothelial cells of BBTB as well as glioma cells illuminated ligand-modified liposomes for pinpoint spatial delivery into glioma. The widely accepted peptide c(RGDyK)-modified liposome loading AL3810 of multiple dosing caused hypothermia, activated anti-c(RGDyK)-liposome IgG and IgM antibody and pertinent complements C3b and C5b-9, and experienced complement-dependent opsonization. We newly proposed a pentapeptide mn with superb αvß3-binding affinity and tailored AL3810-loaded mn-modified liposome that afforded impervious blood circulation, targeting ability, and glioma therapeutic expertise as vastly alleviated immune opsonization on the underpinning of the finite antibodies and complements assembly. Stemming from attenuated immunogenicity, peptide mn strengthened liposome functions as a promising nanocarrier platform for molecular targeting agents.

ɑvß3-targeted liposomal drug delivery system with attenuated immunogenicity enabled by linear pentapeptide for glioma therapy.

Owing to the binding capacity to ɑvß3 integrin overexpressed on glioma, vasculogenic mimicry and neovasculature, the peptide c(RGDyK) has been exploited pervasively to functionalize nanocarriers for targeted delivery of bioactives. The former study in our group substantiated the immunotoxicity of c(RGDyK)-modified liposome, and this unfavorable immunogenicity is known to compromise blood circulation, targeting efficacy and therapeutic outcome. Therefore, we need to find a superior alternative ligand in order to evade the exquisite immuno-sensitization. We developed mn by structure-guided peptide design and retro-inverso isomerization technique, which was experimentally substantiated to have exceptional binding affinity to ɑvß3 integrin. Besides mn does not have affinity toward normal liver cells and kidney cells, which c(RGDyK) possesses in a certain degree. Warranting that mn and c(RGDyK) anchored ɑvß3, we formulated peptide-tethered liposomes and investigated in vivo bio-fate. Compared with c(RGDyK)-modified liposome, mn-modified liposome presented longer blood circulation and reduced ingestion by Kupffer cells with decreased retention in liver accordingly, benefitting from attenuated anti-liposome IgG and IgM response elicited by multiple sequential doses. Those merits strengthened the anti-glioma efficacy of ɑvß3-targeted doxorubicin-loaded liposomes, proving the importance of immunocompatibility in process of targeted drug delivery.

All-stage precisional glioma targeted therapy enabled by a well-designed D-peptide.

Uncontrollable cell proliferation and irreversible neurological damage make glioma one of the most deadly diseases in clinic. Besides the multiple biological barriers, glioma stem cells (GSCs) that are responsible for the maintenance and recurrence of tumor tissues also hinder the therapeutic efficacy of chemotherapy. Therefore, all-stage precisional glioma targeted therapy regimens that could efficiently deliver drugs to glioma cells and GSCs after overcoming multiple barriers have received increasing scrutiny. Methods: A polymeric micelle-based drug delivery system was developed by modifying a "Y-shaped" well-designed ligand of both GRP78 protein and quorum sensing receptor to achieve all-stage precisional glioma targeting, then we evaluated the targeting ability and barrier penetration ability both in vitro and in vivo. In order to achieve all-stage precisional therapy, we need kill both GSCs and glioma related cells. Parthenolide (PTL) has been investigated for its selective toxicity to glioma stem cells while Paclitaxel (PTX) and Temozolomide (TMZ) are widely used in experimental and clinical therapy of glioma respectively. So the in vivo anti-glioma effect of combination therapy was evaluated by Kaplan-Meier survival analysis and immunohistochemical (IHC) examination of tumor tissues. Results: The "Y-shaped" well-designed peptide, termed DWVAP, exhibited excellent glioma (and GSCs) homing and barrier penetration ability. When modified on micelle surface, DWVAP peptide significantly enhanced accumulation of micelles in brain and glioma. In addition, DWVAP micelles showed no immunogenicity and cytotoxicity, which could guarantee their safety when used in vivo. Treatment of glioma-bearing mice with PTL loaded DWVAP modified PEG-PLA micelles plus PTX loaded DWVAP modified PEG-PLA micelles or PTL loaded DWVAP modified PEG-PLA micelles plus TMZ showed improved anti-tumor efficacy in comparison to PTL and PTX loaded unmodified micelles or PTL loaded unmodified micelles plus TMZ. Conclusion: Combination of all-stage targeting strategy and concomitant use of chemotherapeutics and stem cell inhibitors could achieve precise targeted therapy for glioma.

Deliver anti-PD-L1 into brain by p-hydroxybenzoic acid to enhance immunotherapeutic effect for glioblastoma.

In glioblastoma with typical immunosuppressive characteristics, immune checkpoint inhibitors treatment showed unsatisfactory clinical effects, attributable to the exclusion of antibodies by blood-brain barrier (BBB) to a large extent. Herein, a conjugate of anti-programmed death ligand 1 antibody (αPDL1) and the targeting moiety p-hydroxybenzoic acid (pHA) was designed to realize crossing BBB of antibody based on the dopamine receptor mediated transcytosis. Conjugation with pHA did not influence the binding affinity of αPDL1 with PD-L1 protein, thus maintaining the capability of PD pathway blockade. Importantly, pHA-αPDL1 crossed BBB, demonstrated by the increased distribution in both the brain and the glioma after intravenous administration of pHA-αPDL1. Compared with the unmodified αPDL1, pHA-αPDL1 prolonged the survival time and suppressed tumor growth more effectively in an orthotopic glioblastoma model by activating glioma-infiltrating T cells. Our results suggested the potential of the antibody-pHA conjugate to improve efficacy for cerebral diseases by providing a potential platform for macromolecules to play therapeutics role in the brain.

Baicalein enhances the antitumor efficacy of docetaxel on nonsmall cell lung cancer in a ß-catenin-dependent manner.

The side effects of docetaxel have limited its antitumor performances in the treatment of nonsmall cell lung cancer (NSCLC). To address the problem, baicalein, a bioactive flavone that exhibits antitumor activity, was combined with docetaxel so as to achieve better efficacy and lower toxicity. The combination treatment enhanced the stabilization of microtubules and halted the cell-cycle progression, thus synergistically inhibiting the proliferation and inducing the apoptosis of A549 cells and Lewis lung carcinoma cells. The decreased expression of Cyclin-dependent kinase 6 and Cyclin B1 confirmed its regulation in cell cycle, with ß-catenin being an important upstream effector, as evidenced by the decreased expression in the cytoplasm and nucleus as well as the attenuated aggregation in the nucleus. Furthermore, baicalein plus docetaxel evinced better antitumor efficacy by the suppressed tumor growth, increased apoptosis, and decreased tumor angiogenesis in vivo, with no increased toxicity discovered in both tumor-bearing and non-tumor-bearing mice, and an improvement in therapeutic index. This study has demonstrated that baicalein plus docetaxel is an appropriate combination simultaneously with augmented antitumor efficacy and acceptable safety, which might be a promising strategy for patients with advanced NSCLC.

Ligand-Modified Cell Membrane Enables the Targeted Delivery of Drug Nanocrystals to Glioma.

The safe and efficient delivery of chemotherapeutic agents remains critical to anticancer therapy. Herein, we report on a targeted drug delivery system based upon a modified cell membrane coating technique and drug nanocrystals (NCs). Specifically, red blood cell (RBC) membrane was modified with targeting peptides through a facile insertion method involving avidin-biotin interactions. The RBC membrane-coated drug NCs (RBC-NCs) exhibited high drug loading, long-term stability, excellent biocompatibility, and prolonged retention time, all of which make them suitable for effective drug delivery. When modified with the tumor-targeting peptide c(RGDyK), the resulting RGD-RBC-NCs showed superior tumor accumulation and therapeutic efficacy both in mice bearing a subcutaneous tumor as well as orthotropic glioma. RBC-NC therapeutics can be readily generalized to the delivery of various drugs and for the treatment of a wide range of cancers.

Myristic Acid-Modified DA7R Peptide for Whole-Process Glioma-Targeted Drug Delivery.

The clinical treatment of aggressive glioma has been a great challenge, mainly because of the complexity of the glioma microenvironment and the existence of the blood-brain tumor barrier (BBTB)/blood-brain barrier (BBB), which severely hampers the effective accumulation of most therapeutic agents in the glioma region. Additionally, vasculogenic mimicry (VM), angiogenesis, and glioma stem cells (GSC) in malignant glioma also lead to the failure of clinical therapy. To address the aforementioned issues, a whole-process glioma-targeted drug delivery strategy was proposed. The DA7R peptide has effective BBTB-penetrating and notable glioma-, angiogenesis-, and VM-targeting abilities. Herein, we designed a myristic acid modified DA7R ligand (MC-DA7R), which combines tumor-homing DA7R with BBB-penetrable MC. MC-DA7R was then immobilized to PEGylated liposomes (MC-DA7R-LS) to form a whole-process glioma-targeting system. MC-DA7R-LS exhibited exceptional internalization in glioma, tumor neovascular, and brain capillary endothelial cells. Enhanced BBTB- and BBB-traversing efficiencies were also observed on MC-DA7R-LS. Ex vivo imaging on brain tumors also demonstrated the feasibility of MC-DA7R-LS in intracranial glioma-homing, whereas the immunofluorescence studies demonstrated its GSC and angiogenesis homing. Furthermore, doxorubicin-loaded MC-DA7R-LS accomplished a remarkable therapeutic outcome, as a result of a synergistic improvement on the glioma microenvironment. Our study highlights the potential of the MC-modified DA7R peptide as a great candidate for the whole-process glioma-targeted drug delivery.

Enhanced Glioblastoma Targeting Ability of Carfilzomib Enabled by a DA7R-Modified Lipid Nanodisk.

The robust proliferation of tumors relies on a rich neovasculature for nutrient supplies. Therefore, a basic strategy of tumor targeting therapy should include not only killing regular cancer cells but also blocking tumor neovasculature. D-peptide DA7R, which was previously reported to specifically bind vascular endothelial growth factor receptor 2 (VEGFR2) and neuropilin-1 (NRP-1), could achieve the goal of multitarget recognition. Accordingly, the main purposes of this work were to establish a carfilzomib-loaded lipid nanodisk modified with multifunctional peptide DA7R (DA7R-ND/CFZ) and to evaluate its anti-glioblastoma efficacy in vitro and in vivo. It is testified that the DA7R peptide-conjugated lipid nanodisk can be specifically taken up by U87MG cells and HUVECs. Furthermore, DA7R-ND demonstrated a more enhanced penetration than that of the nonmodified formulation on the tumor spheroid model in vitro and more tumor region accumulation in vivo on the subcutaneous and intracranial tumor-bearing nude mice model. DA7R-ND was shown to co-localize with tumor neovasculature in vivo. When loaded with proteasome inhibitor carfilzomib, the DA7R-decorated nanodisk could remarkably suppress tumor proliferation, extend survival time of nude mice bearing an intracranial tumor, and inhibit neovasculature formation with an efficacy higher than that of the nonmodified nanodisk in vitro and in vivo. The present study verified that the heptapeptide DA7R-conjugated nanodisk is a promising nanocarrier for glioblastoma targeting therapy.

A novel peptide ligand RAP12 of LRP1 for glioma targeted drug delivery.

The receptor associated protein (RAP) is a 39 kDa chaperone protein, binding tightly to low-density lipoprotein receptor-related protein-1 (LRP1) that is overexpressed in glioma, tumor neovasculature, vasculogenic mimicry (VM), the blood-brain barrier (BBB) and the blood-brain tumor barrier (BBTB). Herein, we miniaturized the RAP protein into a short peptide RAP12 (EAKIEKHNHYQK) aiding by computer-aided peptide design technique. RAP12 contained the essential lysines at the positions 253 and 256. The binding affinity of RAP12 to LRP1 was theoretically and experimentally evaluated. In cellular level, RAP12 could effectively internalize into U87, HUVEC and bEnd.3 cells. When modified on the surface of PEG-PLA micelles (RAP12-PEG-PLA), RAP12 could effectively facilitate the penetration of micelles through the BBB/BBTB in vitro/vivo. Paclitaxel-loaded RAP12-PEG-PLA could remarkably inhibit the growth of glioma cells and the formation of tumor neovasculature and VM, significantly prolong the median survival time of nude mice bearing intracranial glioma in comparison to model mice treated with plain micelles or Taxol. These results suggested that the RAP12 held the potential for multifunctional glioma-targeted drug delivery.

Cholera Toxin Subunit B Enabled Multifunctional Glioma-Targeted Drug Delivery.

Glioma is among the most formidable brain cancers due to location in the brain. Cholera toxin subunit B (CTB) is investigated to facilitate multifunctional glioma-targeted drug delivery by targeting the glycosphingolipid GM1 expressed in the blood-brain barrier (BBB), neovasulature, and glioma cells. When modified on the surface of poly(lactic-co-glycolic acid) (PLGA) nanoparticles (CTB-NPs), CTB fully retains its bioactivity after 24 h incubation in the fresh mouse plasma. The formed protein corona (PC) of CTB-NP and plain PLGA nanoparticles (NP) after incubation in plasma is analyzed using liquid chromatography tandem massspectrometry (nano-LC-MS/MS). CTB modification does not alter the protein components of the formed PC, macrophage phagocytosis, or pharmacokinetic profiles. CTB-NP can efficiently penetrate the in vitro BBB model and target glioma cells and human umbilical vascular endothelial cells. Paclitaxel is loaded in NP (NP/PTX) and CTB-NP (CTB-NP/PTX), and their antiglioma effects are assessed in nude mice bearing intracranial glioma. CTB-NP/PTX can efficiently induce apoptosis of intracranial glioma cells and ablate neovasulature in vivo, resulting in significant prolongation of survival of nude mice bearing intracranial glioma (34 d) in comparison to those treated with NP/PTX (29 d), Taxol (24 d), and saline (21 d). The present study suggests a potential multifunctional glioma-targeted drug delivery system enabled by cholera toxin subunit B.

A facile approach to functionalizing cell membrane-coated nanoparticles with neurotoxin-derived peptide for brain-targeted drug delivery.

The blood brain barrier separates the circulating blood from the extracellular fluid in the central nervous system and thus presents an essential obstacle to brain transport of therapeutics. Herein, we report on an effective brain-targeted drug delivery system that combines a robust red blood cell membrane-coated nanoparticle (RBCNP) with a unique neurotoxin-derived targeting moiety. The RBCNPs retain the complex biological functions of natural cell membranes while exhibiting physicochemical properties that are suitable for effective drug delivery. CDX peptide is derived from candoxin and shows high binding affinity with nicotinic acetylcholine receptors (nAChRs) expressed on the surface of brain endothelial cells. Through a facile yet robust approach, we successfully incorporate DCDX peptides onto the surface of RBCNPs without compromising the peptide's brain targeting ability. The resulting DCDX-RBCNPs show promising brain targeting efficiency both in vitro and in vivo. Using a glioma mouse model, we demonstrate that doxorubicin-loaded DCDX-RBCNPs have superior therapeutic efficacy and markedly reduced toxicity as compared to the nontargeted drug formulations. While RBCNPs are used as a model system to evaluate the surface modification approach, the reported method can be readily generalized to various types of cell membrane-derived nanocarriers for broad medical applications.

Liposome-based glioma targeted drug delivery enabled by stable peptide ligands.

The treatment of glioma is one of the most challenging tasks in clinic. As an intracranial tumor, glioma exhibits many distinctive characteristics from other tumors. In particular, various barriers including enzymatic barriers in the blood and brain capillary endothelial cells, blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB) rigorously prevent drug and drug delivery systems from reaching the tumor site. To tackle this dilemma, we developed a liposomal formulation to circumvent multiple-barriers by modifying the liposome surface with proteolytically stable peptides, (D)CDX and c(RGDyK). (D)CDX is a D-peptide ligand of nicotine acetylcholine receptors (nAChRs) on the BBB, and c(RGDyK) is a ligand of integrin highly expressed on the BBTB and glioma cells. Lysosomal compartments of brain capillary endothelial cells are implicated in the transcytosis of those liposomes. However, both peptide ligands displayed exceptional stability in lysosomal homogenate, ensuring that intact ligands could exert subsequent exocytosis from brain capillary endothelial cells and glioma targeting. In the cellular uptake studies, dually labeled liposomes could target both brain capillary endothelial cells and tumor cells, effectively traversing the BBB and BBTB monolayers, overcoming enzymatic barrier and targeting three-dimensional tumor spheroids. Its targeting ability to intracranial glioma was further verified in vivo by ex vivo imaging and histological studies. As a result, doxorubicin liposomes modified with both (D)CDX and c(RGDyK) presented better anti-glioma effect with prolonged median survival of nude mice bearing glioma than did unmodified liposomes and liposomes modified with individual peptide ligand. In conclusion, the liposome suggested in the present study could effectively overcome multi-barriers and accomplish glioma targeted drug delivery, validating its potential value in improving the therapeutic efficacy of doxorubicin for glioma.

Local delivery of minocycline-loaded PEG-PLA nanoparticles for the enhanced treatment of periodontitis in dogs.

BACKGROUND: Rapid local drug clearance of antimicrobials is a major drawback for the treatment of chronic periodontitis. In the study reported here, minocycline-loaded poly(ethylene glycol)-poly(lactic acid) nanoparticles were prepared and administered locally for long drug retention and enhanced treatment of periodontitis in dogs. METHODS: Biodegradable poly(ethylene glycol)-poly(lactic acid) was synthesized to prepare nanoparticles using an emulsion/solvent evaporation technique. The particle size and zeta potential of the minocycline-loaded nanoparticles (MIN-NPs) were determined by dynamic light scattering and the morphology of the nanoparticles was observed by transmission electron microscopy. The in vitro release of minocycline from MIN-NPs and in vivo pharmacokinetics of minocycline in gingival crevice fluid, after local administration of MIN-NPs in the periodontal pockets of beagle dogs with periodontitis, were investigated. The anti-periodontitis effects of MIN-NPs on periodontitis-bearing dogs were finally evaluated. RESULTS: Transmission electron microscopy examination and dynamic light scattering results revealed that the MIN-NPs had a round shape, with a mean diameter around 100 nm. The in vitro release of minocycline from MIN-NPs showed a remarkably sustained releasing characteristic. After local administration of the MIN-NPs, minocycline concentration in gingival crevice fluid decreased slowly and retained an effective drug concentration for a longer time (12 days) than Periocline(®). Anti-periodontitis effects demonstrated that MIN-NPs could significantly decrease symptoms of periodontitis compared with Periocline and minocycline solution. These findings suggest that MIN-NPs might have great potential in the treatment of periodontitis.