Tingting Lv

Role of generation on folic acid-modified poly(amidoamine) dendrimers for targeted delivery of baicalin to cancer cells

Baicalin (BAI) has been reported to exert antitumor effects. However, BAI has limited water solubility, non-specific tumor targeting, and low bioavailability, which severely limited its clinical application. The aim of this study was to develop folic acid (FA) covalently conjugated-polyamidoamine (PAMAM) dendrimers (PAMAM-FA) as carrier systems for improvement of water solubility and tumor-specificity of BAI, and study the role of generation on the physiochemical properties and biological effects of PAMAM-FA/BAI complexes. In this work, four generations of PAMAM-FA were synthesized to entrap BAI. The average sizes of G3-FA/BAI, G4-FA/BAI, G5-FA/BAI, and G6-FA/BAI complexes were 174.4nm, 184.5nm, 258.8nm, and 247.5nm, respectively, and the zeta potentials of four PAMAM-FA/BAI complexes were -2.9mV, -6.6mV, -9.3mV, -9.0mV, respectively. The entrapment efficiencies of four PAMAM-FA/BAI complexes were 91.1%, 53.5%, 80.3%, and 91.9%, respectively, and the drug loading of PAMAM-FA/BAI complexes were about 22%. The formed PAMAM-FA/BAI complexes allowed sustained release of BAI in acidic PBS (pH5.4). In cellular uptake assay, PAMAM-FA/BAI complexes demonstrated increased drug uptake level in folate receptor (FR)-positive Hela cancer cells than FR-negative A549 cells, and the cellular uptake efficiency of PAMAM-FA is closely related with the generation of PAMAM. The MTT assay results showed that PAMAM-FA/BAI complexes demonstrated enhanced toxicity against Hela cells than non-FA-modified PAMAM/BAI complexes, and the G6-FA/BAI demonstrated the best inhibition efficiency. The cell cycle and cell apoptosis analysis further demonstrated the tumor-specific therapeutic efficacy of PAMAM-FA/BAI. These results suggested that the PAMAM-FA have the potential for targeted delivery of BAI into cancer cells to enhance its anti-tumor efficacy.

Chitosan-based nanoparticles for improved anticancer efficacy and bioavailability of mifepristone

In addition to its well-known abortifacient effect, mifepristone (MIF) has been used as an anticancer drug for various cancers in many studies with an in-depth understanding of the mechanism of action. However, application of MIF is limited by its poor water solubility and low oral bioavailability. In this work, we developed a drug delivery system based on chitosan nanoparticles (CNs) to improve its bioavailability and anticancer activity. The MIF-loaded chitosan nanoparticles (MCNs) were prepared by convenient ionic gelation techniques between chitosan (Cs) and tripolyphosphate (TPP). The preparation conditions, including Cs concentration, TPP concentration, Cs/MIF mass ratio, and pH value of the TPP solution, were optimized to gain better encapsulation efficiency (EE) and drug loading capacity (DL). MCNs prepared with the optimum conditions resulted in spherical particles with an average size of 200 nm. FTIR and XRD spectra verified that MIF was successfully encapsulated in CNs. The EE and DL of MCNs determined by HPLC were 86.6% and 43.3%, respectively. The in vitro release kinetics demonstrated that MIF was released from CNs in a sustained-release manner. Compared with free MIF, MCNs demonstrated increased anticancer activity in several cancer cell lines. Pharmacokinetic studies in male rats that were orally administered MCNs showed a 3.2-fold increase in the area under the curve from 0 to 24 h compared with free MIF. These results demonstrated that MCNs could be developed as a potential delivery system for MIF to improve its anticancer activity and bioavailability.

Aptamer-Conjugated Chitosan-Anchored Liposomal Complexes for Targeted Delivery of Erlotinib to EGFR-Mutated Lung Cancer Cells.

Lung cancer is the leading cancer and has the highest death rate. The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) erlotinib has had a promising response in lung cancer therapy. Unfortunately, individuals with TKI-resistant EGFR mutations often develop acquired resistance against erlotinib. To overcome this resistance, in the present study, we developed liposomes anchored with anti-EGFR aptamer (Apt)-conjugated chitosan (Apt-Cs) as stable carriers to deliver erlotinib to the target. We loaded erlotinib into Apt-Cs-anchored liposomal complexes (Apt-CL-E) and characterized the physicochemistry of Apt-CL-E. The nanoparticles showed good biostability and a binding specificity for EGFR-mutated cancer cells guided by the Apt. The specific binding facilitated the uptake of Apt-CL-E into EGFR-mutated cancer cells. A cytotoxicity study showed an advantage of Apt-CL-E over their nontargeted liposomal counterparts in delivering erlotinib to EGFR-mutated cancer cells, resulting in cell cycle arrest and apoptosis. These results provide a good platform for future in vivo animal studies with Apt-CL-E.

Folate and Heptamethine Cyanine Modified Chitosan-Based Nanotheranostics for Tumor Targeted Near-Infrared Fluorescence Imaging and Photodynamic Therapy

Folate (FA) and heptamethine cyanine (Cy7)-modified chitosan (CF7) was synthesized by click chemistry and its self-assembled nanoparticles (CF7Ns) were developed for tumor-specific imaging and photodynamic therapy. The characterization spectrum confirmed CF7 had a good FA and Cy7 conjugation efficacy. The diameter of CF7Ns measured by DLS was about 291.6 nm, and the morphology observed with AFM showed filamentous clusters of particles. The results of targeting ability of CF7Ns demonstrated enhanced targeting behaviors of CF7Ns compared with non-FA-modified nanoparticles C7Ns in FA receptor-positive HeLa cells. The cytotoxicity and cell apoptosis assay showed that CF7Ns under near-infrared light irradiation led to more apoptotic cell death in HeLa cells to improve the therapeutic efficacy. The mechanisms of the photodynamic effects of CF7Ns were demonstrated through measurement of intracellular reactive oxygen species and the apoptosis-related cytokines. These results suggested that CF7Ns are promising tumor targeting carriers for simultaneous fluorescence imaging and photodynamic therapy.

Erlotinib-Guided Self-Assembled Trifunctional Click Nanotheranostics for Distinguishing Druggable Mutations and Synergistic Therapy of Nonsmall Cell Lung Cancer

The outcome of molecular targeted therapies is restricted by the ambiguous molecular subtypes of nonsmall cell lung cancer (NSCLC), which are difficult to be defined with druggable mutations, and the inevitable emergence of drug-resistance. Here we used the Cu-catalyzed click chemistry to synthesize a chitosan-based self-assembled nanotheranostics (CE7Ns) composed of a near-infrared (NIR) fluorescent photosensitizer Cy7 and molecular targeted drug erlotinib. The well-characterized CE7Ns can release erlotinib and Cy7 fast under acidic condition in the presence of lysozyme, distinguish three molecular subtypes of NSCLC, and specifically bind to the erlotinib-sensitive epidermal growth factor receptor (EGFR)-mutated PC-9 cells. The uptake of CE7Ns is much more in PC-9 cells than in other NSCLC cells, thus generating a notable fluorescence signal in PC-9 cells. Upon NIR irradiation, Cy7 in CE7Ns produces high reactive oxygen species in PC-9 cells. The synergistic effect between erlotinib-targeted therapy and photodynamic therapy significantly up-regulates cancer suppressor p53 and inhibits Survivin, which results in more apoptosis and cell cycle arrest. Upon intravenous administration, the erlotinib-guided CE7Ns significantly accumulate in PC-9-seeded mouse lungs and produce strong fluorescence. Upon NIR irradiation, CE7Ns significantly inhibit the subcutaneously implanted PC-9 tumor growth. This study provides, for the first time, a novel strategy to synthesize a multifunctional theranostic entity to simultaneously distinguish and image druggable mutations and combine targeted therapy with photodynamic therapy to overcome drug resistance.

Construction and biological evaluation of different self-assembled nanoarchitectures of FZU-03,010

&NA; Chemotherapy is currently one of the promising therapeutic methods for non‐small‐cell lung cancer (NSCLC), but the emergence of multidrug resistance (MDR) is the greatest obstacle to efficient drug delivery for successful chemotherapy. Nanotechnology‐based drug delivery holds great promise to promote intracellular drug delivery to reverse MDR. In this work, we used our previously synthesized ursolic acid (UA) derivative, FZU‐03,010 (F3), to prepare nanodrugs of F3 with different architectures and study the role of the structure on the physiochemical properties and the biological effects against A549 and its PTX‐resistant A549/PTX lung cancer cells. Using different preparation methods, amphiphilic F3 could self‐assemble into different structures such as nanoaggregates (F3‐NA), vesicles (F3‐VC), or nanoparticles (F3‐NP) with different physiochemical properties. The self‐assembled nanodrugs could be utilized for the entrapment of fluorophores and showed different cellular uptake efficiencies. The cytotoxicity results demonstrated that compared with UA, F3‐NA and F3‐NP could suppress A549 and A549/PTX cells viability more potently at lower concentration. In addition, F3‐NA and F3‐NP could induce G1 cell cycle arrest, cell apoptosis and caspase‐3 activation more efficiently than that of UA. Furthermore, F3‐NA and F3‐NP could effectively inhibit PI3K/Akt pathway and decrease the expression of Bcl‐2 and the cell cycle‐dependent kinase inhibitors p‐ERK1/2 and Cyclin D1 in both A549 and A549/PTX cells. In conclusion, our results suggest that the UA derivative F3 is more potent in inhibiting cancer cell proliferation, and F3‐NA and F3‐NP have the potential to be developed as a therapeutic agent for resistant NSCLC cells. Graphical Abstract Figure. No caption available.

Challenges and opportunities from basic cancer biology for nanomedicine for targeted drug delivery

BACKGROUND Effective cancer therapy is still a great challenge for modern medical research due to the complex underlying mechanisms of tumorigenesis and tumor metastasis, and the limitations commonly associated with currently used cancer therapeutic options. Nanotechnology has been implemented in cancer therapeutics with immense potential for improving cancer treatment. OBJECTIVE Through information about the recent advances regarding cancer hallmarks, we could comprehensively understand the pharmacological effects and explore the mechanisms of the interaction between the nanomaterials, which could provide opportunities to develop mechanism-based nanomedicine to treat human cancers. METHODS We collected related information and data from articles. RESULTS In this review, we discussed the characteristics of cancer including tumor angiogenesis, abnormalities in tumor blood vessels, uncontrolled cell proliferation markers, multidrug resistance, tumor metastasis, cancer cell metabolism, and tumor immune system that provide opportunities and challenges for nanomedicine to be directed to specific cancer cells and portray the progress that has been accomplished in application of nanotechnology for cancer treatment. CONCLUSION The information presented in this review can provide useful references for further studies on developing effective nanomedicine for the treatment of cancer.

Chloroquine in combination with aptamer-modified nanocomplexes for tumor vessel normalization and efficient erlotinib/Survivin shRNA co-delivery to overcome drug resistance in EGFR-mutated non-small cell lung cancer

Although novel molecular targeted drugs have been recognized as an effective therapy for non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) activating mutations, their efficacy fails to meet the expectation due to the acquired resistance in tumors. Up-regulation of the anti-apoptotic protein Survivin was shown to contribute to the resistance to EGFR tyrosine kinase inhibitors (TKI) in EGFR mutation-positive NSCLC. However, the unorganized tumor blood vessels impeded drug penetration into tumor tissue. The resulting insufficient intracellular drug/gene delivery in drug-resistant cancer cells remarkably weakened the drug efficacy in NSCLC. In this work, a multi-functional drug delivery system AP/ES was developed by using anti-EGFR aptamer (Apt)-modified polyamidoamine to co-deliver erlotinib and Survivin-shRNA. Chloroquine (CQ) was used in combination with AP/ES to normalize tumor vessels for sufficient drug/gene delivery to overcome drug resistance in NSCLC cells. The obtained AP/ES possessed desired physicochemical properties, good biostability, controlled drug release profiles, and strong selectivity to EGFR-mutated NSCLC mediated by Apt. CQ not only enhanced endosomal escape ability of AP/ES for efficient gene transfection to inhibit Survivin, but also showed strong vessel-normalization ability to improve tumor microcirculation, which further promoted drug delivery and enhanced drug efficacy in erlotinib-resistant NSCLC cells. Our innovative gene/drug co-delivery system in combination with CQ showed a promising outcome in fighting against erlotinib resistance both in vitro and in vivo. This work indicates that normalization of tumor vessels could help intracellular erlotinib/Survivin-shRNA delivery and the down-regulation of Survivin could act synergistically with erlotinib for reversal of erlotinib resistance in EGFR mutation-positive NSCLC. STATEMENT OF SIGNIFICANCE NSCLC patients who benefited from EGFR-TKIs inevitably developed acquired resistance. Previous research focused on synthesis of new generation of molecular targeted drugs that could irreversibly inhibit EGFR with a particular gene mutation to overcome drug resistance. However, they failed to inhibit EGFR with other gene mutations. Activation of bypass signaling pathway and the changes of tumor microenvironment are identified as two of the mechanisms of acquired resistance to EGFR-TKIs. We therefore constructed multifunctional gene/drug co-delivery nanocomplexes AP/ES co-formulated with chloroquine that could target the both two mechanisms. We found that chloroquine not only enhanced endosomal escape ability of AP/ES for efficient gene transfection to inhibit Survivin, but also showed strong vessel-normalization ability to improve tumor microcirculation, which further promoted drug delivery into tumor tissue and enhanced drug efficacy in erlotinib-resistant NSCLC.