Self-Assembled Chlorin e6 Conjugated Chondroitin Sulfate Nanodrug for Photodynamic Therapy

Photosensitizer-Conjugated Hyaluronic Acid-Shielded Polydopamine Nanoparticles for Targeted Photomediated Tumor Therapy

Photodynamic therapy (PDT) is a widely used clinical option for tumor therapy. However, the clinical utilization of conventional small-molecule photosensitizers (PSs) for PDT has been limited by their low selectivity for disease sites, and undesirable photoactivation. To overcome these limitations, we demonstrated a tumor-specific and photoactivity-controllable nanoparticle photomedicine based on a combination of PS-biomacromolecule conjugates and polydopamine nanoparticles (PD-NP) for an effective tumor therapy. This novel photomedicine consisted of a PD-NP core and a PS-conjugated hyaluronic acid (PS-HA) shell. The PD-NP and the PS-HA play roles as a quencher for PSs and a cancer targeting moiety, respectively. The synthesized PS-HA-shielded PD-NPs (PHPD-NPs) had a relatively narrow size distribution (approximately 130 nm) with uniform spherical shapes. In response to cancer-specific intracellular enzymes (e.g., hyaluronidase), the PHPD-NPs exhibited an excellent singlet oxygen generation capacity for PDT. Furthermore, an efficient photothermal conversion ability for photothermal therapy (PTT) was also shown in the PHPD-NPs system. These properties provide superior therapeutic efficacy against cancer cells. In mice tumor model, the photoactive restorative effects of the PHPD-NPs were much higher in cancer microenvironments compared to that in the normal tissue. As a result, the PHPD-NPs showed a significant antitumor activity in in vivo mice tumor model. The nanoparticle photomedicine design is a novel strategy for effective tumor therapy.

Distinct CPT-induced deaths in lung cancer cells caused by clathrin-mediated internalization of CP micelles

We previously synthesized a chondroitin sulfate-graft-poly(ε-caprolactone) copolymer (H-CP) with a high content of poly(ε-caprolactone) (18.7 mol%), which self-assembled in water into a rod-like micelle to encapsulate hydrophobic camptothecin (CPT) in the core (micelle/CPT) for tumor-targeted drug delivery. As a result of the recognition of the micelle by CD44, the micelle/CPT entered CRL-5802 cells efficiently and released CPT efficaciously, resulting in higher tumor suppression than commercial CPT-11. In this study, H1299 cells were found to have a higher CD44 expression than CRL-5802 cells. However, the lower CD44-expressing CRL-5802 cells had a higher percentage of cell death and higher cellular uptake of the micelle/CPT than the higher CD44-expressing H1299 cells. Examination of the internalization pathway of the micelle/CPT in the presence of different endocytic chemical inhibitors showed that the CRL-5802 cells involved clathrin-mediated endocytosis, which was not found in the H1299 cells. Analysis of the cell cycle of the two cell lines exposed to the micelle/CPT revealed that the CRL-5802 cells arrested mainly in the S phase and the H1299 cells arrested mainly in the G2-M phase. A consistent result was also found in the evaluation of γ-H2AX expression, which was about three-fold higher in the CRL-5802 cells than in the H1299 cells. A near-infrared dye, IR780, was encapsulated into the micelle to observe the in vivo biodistribution of the micelle/IR780 in tumor-bearing mice. The CRL-5802 tumor showed a higher fluorescence intensity than the H1299 tumor at any tracing time after 1 h. Thus we tentatively concluded that CRL-5802 cells utilized the clathrin-mediated internalization pathway and arrested in the S phase on exposure to the micelle/CPT; all are possible reasons for the better therapeutic outcome in CRL-5802 cells than in H1299 cells.

The mitochondria-targeted and IR780-regulated theranosomes for imaging and enhanced photodynamic/photothermal therapy

(a) A schematic of the system TPP-IR780/Ce6-TNS. (b) Illustration of the system TPP-IR780/Ce6-TNS to the tumor microenvironment.

Nano-assembly of bovine serum albumin driven by rare-earth-ion (Gd) biomineralization for highly efficient photodynamic therapy and tumor imaging

Biomineralization of a rare earth ion (Gd) is first employed to assemble BSA into sub-50 nm nanoparticles (Gd@BSA) for theranostic applications.

Lipid micelles packaged with semiconducting polymer dots as simultaneous MRI/photoacoustic imaging and photodynamic/photothermal dual-modal therapeutic agents for liver cancer

Semiconducting polymer dot micelles for MRI/photoacoustic imaging and single-laser-induced PDT/PTT therapy.

Bile acid-conjugated chondroitin sulfate A-based nanoparticles for tumor-targeted anticancer drug delivery

Chondroitin sulfate A-deoxycholic acid (CSA-DOCA)-based nanoparticles (NPs) were produced for tumor-targeted delivery of doxorubicin (DOX). The hydrophobic deoxycholic acid (DOCA) derivative was conjugated to the hydrophilic chondroitin sulfate A (CSA) backbone via amide bond formation, and the structure was confirmed by (1)H-nuclear magnetic resonance (NMR) analysis. Loading the DOX to the CSA-DOCA NPs resulted in NPs with an approximately 230nm mean diameter, narrow size distribution, negative zeta potential, and relatively high drug encapsulation efficiency (up to 85%). The release of DOX from the NPs exhibited sustained and pH-dependent release profiles. The cellular uptake of DOX from the CSA-DOCA NPs in CD44 receptor-positive human breast adenocarcinoma MDA-MB-231 cells was reduced when co-treated with free CSA, indicating the interaction between CSA and the CD44 receptor. The lower IC50 value of DOX from the CSA-DOCA NPs compared to the DOX solution was also probably due to this interaction. Moreover, the ability of the developed NPs to target tumors could be inferred from the in vivo and ex vivo near-infrared fluorescence (NIRF) imaging results in the MDA-MB-231 tumor-xenografted mouse model. Both passive and active strategies appear to have contributed to the in vivo tumor targetability of the CSA-DOCA NPs. Therefore, these CSA-DOCA NPs could further be developed into a theranostic nanoplatform for CD44 receptor-positive cancers.

Novel pH-sensitive nanoformulated docetaxel as a potential therapeutic strategy for the treatment of cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CC) is one of the fatal malignant neoplasms with poor prognosis. The traditional chemotherapy has been resistant to CC and does not improve the quality of life. The aim of the present study is to investigate the potential of chondroitin sulphate (CS)-histamine (HS) block copolymer micelles to improve the chemotherapeutic efficacy of docetaxel (DTX).

RESULTS

pH-responsive property of CS-HS micelles was utilized to achieve maximum therapeutic efficacy in CC. In the present study, docetaxel-loaded CS-HS micelles (CSH-DTX) controlled the release of drug in the basic pH while rapidly released its cargo in the tumor pH (pH 5 and 6.8) possibly due to the breakdown of polymeric micelles. A nanosize of <150 nm will allow its accumulation in the tumor interstitial spaces via EPR effect. CSH-DTX effectively killed the cancer kills in a time- and concentration-dependent manner and showed pronounced therapeutic action than that of free drug at all-time points. CSH-DTX resulted in higher apoptosis of cancer cells with ~30% and ~50 of cells in early apoptosis quadrant when treated with 100 and 1000 ng/ml of equivalent drug. The micellar formulations showed remarkable effect in controlling the tumor growth and reduced the overall tumor volume to 1/5(th) to that of control and half to that of free drug treated group with no sign of drug-related adverse effects. Immunohistochemical analysis of tumor sections showed that fewer number of Ki-67 cells were present in CSH-DTX treated group comparing to that of free DTX treated group.

CONCLUSION

Our data suggests that nanoformulation of DTX could potentially improve the chemotherapy treatment in cholangiocarcinoma as well as in other malignancies.

Porphyrin-containing amphiphilic block copolymers for photodynamic therapy

Amphiphilic PNIPAM-b-PTPPC6MA block copolymers as promising photosensitizers for photodynamic therapy (PDT) constructed using porphyrin-containing monomers via RAFT polymerization.

Preparation of chondroitin sulfate-g-poly(ε-caprolactone) copolymers as a CD44-targeted vehicle for enhanced intracellular uptake

Chondroitin sulfate-g-poly(ε-caprolactone) (CP) copolymers were synthesized via atom transfer radical addition (ATRA). The CP copolymers self-assembled into micelles in water, and the micelles could be used to encapsulate a hydrophobic anticancer drug, camptothecin (CPT), in the core for tumor targeting delivery. The physicochemical properties of the micelles and CPT-loaded micelles were thoroughly characterized. For the in vitro test, the CPT release, the protection of the lactone ring of CPT from hydrolysis and the cellular uptake of CPT were studied. The cell-killing and apoptosis-inducing effects using the CPT-loaded micelles were significantly better than using free CPT against CRL-5802 cells. The micellar internalization into CRL-5802 cells was primarily via CD44 and clathrin dual-mediated endocytosis. For the in vivo test, the therapeutic efficacy of the CPT-loaded micelles was studied in a non-small-cell lung cancer xenograft animal model. The CPT-loaded micelles showed good inhibition in tumor growth as compared with a commercial product, CPT-11, in CRL-5802 tumor-bearing mice. The in vitro and in vivo data suggested the CP-based micelles are promising anticancer drug vehicles for lung cancer targeting.

Advanced photodynamic agent from chondroitin sulfate/zinc phthalocyanine conjugate

In order to improve the therapeutic effect of zinc phthalocyanines (ZnPc), a photoactive nanodrug was prepared with acetylated chondroitin sulfate (AcCS), utilizing a simple chemical method. AcCS/ZnPc nanodrugs have a unimodal size distribution below 200 nm and a negative surface charge due to AcCS located on the nanodrug surface. In organic solvent such as DMSO or DMF, it has strong fluorescence intensity and generates abundant singlet oxygen. However, in aqueous solvent, AcCS/ZnPc nanodrugs developed a self-organized form which induced reducing fluorescence intensity and singlet oxygen generation. The cellular uptake of the nanodrug was determined using a cell lysis test and confocal microscopy observation. The results indicated that cellular internalization efficiency of the nanodrug was 1.7–2.1 times higher than that of free ZnPc . Also, the phototoxicity of the nanodrug was detected via MTT assay with or without light. Although free ZnPc did not exhibit cytotoxicity in both light and dark condition, the nanodrug exhibited increasing cytotoxicity after irradiation. We therefore suggest that AcCS/ZnPc nanodrugs may have promising applications as new photodynamic agents for the clinical treatment of various tumors.

Self-assembled liposomal nanoparticles in photodynamic therapy

Photodynamic therapy (PDT) employs the combination of non-toxic photosensitizers (PS) together with harmless visible light of the appropriate wavelength to produce reactive oxygen species that kill unwanted cells. Because many PS are hydrophobic molecules prone to aggregation, numerous drug delivery vehicles have been tested to solubilize these molecules, render them biocompatible and enhance the ease of administration after intravenous injection. The recent rise in nanotechnology has markedly expanded the range of these nanoparticulate delivery vehicles beyond the well-established liposomes and micelles. Self-assembled nanoparticles are formed by judicious choice of monomer building blocks that spontaneously form a well-oriented 3-dimensional structure that incorporates the PS when subjected to the appropriate conditions. This self-assembly process is governed by a subtle interplay of forces on the molecular level. This review will cover the state of the art in the preparation and use of self-assembled liposomal nanoparticles within the context of PDT.

Chondroitin sulfate functionalized mesostructured silica nanoparticles as biocompatible carriers for drug delivery

Mesoporous silica nanoparticles (MSNs) have garnered a great deal of attention as potential carriers for therapeutic payloads. Here, we report a pH-responsive drug-carrier based on chondroitin sulfate functionalized mesostructured silica nanoparticles (NMChS-MSNs) ie, the amidation between NMChS macromer and amino group functionalized MSNs. The prepared nanoparticles were characterized using dynamic light scattering, fourier transform infrared spectroscopy and transmission electron microscopy. The resultant NMChS-MSNs were uniform spherical nanoparticles with a mean diameter of approximately 74 nm. Due to the covalent graft of hydrophilic and pH responsive NMChS, the NMChS-MSNs could be well dispersed in aqueous solution, which is favorable to being utilized as drug carriers to construct a pH-responsive controlled drug delivery system. Doxorubicin hydrochloride (DOX), a well-known anticancer drug, could be effectively loaded into the channels of NMChS-MSNs through electrostatic interactions between drug and matrix. The drug release rate of DOX@NMChS-MSNs was pH dependent and increased with the decrease of pH. The in vitro cytotoxicity test indicated that NMChS-MSNs were highly biocompatible and suitable to use as drug carriers. Our results imply that chondroitin sulfate functionalized nanoparticles are promising platforms to construct the pH-responsive controlled drug delivery systems for cancer therapy.

The controlled photoactivity of nanoparticles derived from ionic interactions between a water soluble polymeric photosensitizer and polysaccharide quencher

In order to design a water soluble polymeric photosensitizer (WPS) with controllable photoactivity, a nano-photosensitizer (NPS) was prepared from a polyelectrolyte complex between polyethylene glycol-polyethylenimine-chlorine e6 conjugate (PEG-PEI-Ce6) and Black Hole Quencher-3 chondroitin sulfate conjugate (BHQ-3-CS). NPSs have a unimodal size distribution below 100 nm. Photoquenching of the NPS was dependent on the weight ratio of BHQ-3-CS/WPS. This phenomenon was maintained in a salt condition up to 300 mm, indicating that the photoactivity of the NPS disappears in the normal blood stream of the body. The quenched photoactivity was restored by the enzyme degradation of BHQ-3-CS after esterase treatment. In a HCT-116 (human colon cancer) cell test, the rapid cellular internalization of the NPS without any other ligands was observed by confocal imaging. Upon light irradiation after internalization, phototoxicity was detected via MTT colorimetric assay. Also, when the NPS was subcutaneously injected in both tumoral and normal regions of HCT-116 tumor-bearing mice, the fluorescence signal in the tumors rapidly increased compared to the normal region due to the enzymatic-triggered dissociation of the NPS in vivo. These results suggest that the NPS can provide both tumor diagnosis and therapy simultaneously, and has great potential for biological studies and clinical treatments of various tumors.