Silk Fibroin-Coated Liposomes as Biomimetic Nanocarrier for Long-Term Release Delivery System in Cancer Therapy

Despite much progress in cancer therapy, conventional chemotherapy can cause poor biodistribution and adverse side-effects on healthy cells. Currently, various strategies are being developed for an effective chemotherapy delivery system. Silk fibroin (SF) is a natural protein used in a wide range of biomedical applications including cancer therapy due to its biocompatibility, biodegradability, and unique mechanical properties. In this study, SF-coated liposomes (SF-LPs) were prepared as a biomimetic drug carrier. Physicochemical properties of SF-LPs were characterized by Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering, zeta potential measurement, and transmission electron microscopy (TEM). In vitro release of SF-LPs loaded with doxorubicin (DOX-SF-LPs) was evaluated over 21 days. Anticancer activity of DOX-SF-LPs was determined against MCF-7 and MDA-MB231 cells using the MTT assay. SF-LPs containing 1% SF exhibited favorable characteristics as a drug carrier. SF coating modified the kinetics of drug release and reduced the cytotoxic effect against L929 fibroblasts as compared to the uncoated liposomes containing cationic lipid. DOX-SF-LPs showed anticancer activity against breast cancer cells after 48 h or 72 h at 20 μM of DOX. This approach provides a potential platform of long-term release that combines biocompatible SF and phospholipids for cancer therapy, achieving efficient drug delivery and reducing side-effects.     

σ-Silane Platinum(II) Complexes as Intermediates in C−Si Bond-Coupling Processes

Platinum complexes [Pt(NHC′)(NHC)][BAr^F] (in which NHC′ denotes a cyclometalated N-heterocyclic carbene ligand, NHC) react with primary silanes RSiH₃ to afford the cyclometalated platinum(II) silyl complexes [Pt(NHC-SiHR′)(NHC)][BAr^F] through a process that involves the formation of C−Si and Pt−Si bonds with concomitant extrusion of H₂. Low-temperature NMR studies indicate that the process proceeds through initial formation of the σ-SiH complexes [Pt(NHC′)(NHC)(HSiH₂R)][BAr^F], which are stable at temperatures below −10 °C. At higher temperatures, activation of one Si−H bond followed by a C−Si coupling reaction generates an agostic SiH platinum hydride derivative [Pt(H)(NHC′-SiH₂R)(NHC)][BAr^F], which undergoes a second Si−H bond activation to afford the final products. Computational modeling of the reaction mechanism indicates that the stereochemistry of the silyl/hydride ligands after the first Si−H bond cleavage dictates the nature of the products, favoring the formation of a C−Si bond over a C−H bond, in contrast to previous results obtained for tertiary silanes. Furthermore, the process involves a trans-to-cis isomerization of the NHC ligand before the second Si−H bond cleavage.     

Immobilization of CoII-(N,N′-bis(salicylidene)-2-aminobenzylamine) on Poly(pyrrole-co-o-anisidine)/Chitosan Composite Films: Application to Electrocatalytic Oxidation of Catechol

In this study, poly (pyrrole-co-o-anisidine)/chitosan composite (Cs) films were prepared by cyclic voltammetry technique on platinum electrode using different pyrrole and o-anisidine mole ratios. Immobilization process was accomplished in Co^II-(N,N′-bis(salicylidene)-2-aminobenzylamine)(CoL) dissolved 0.15 M acetonitrile-LiClO₄ solution by cyclic voltammetry technique at 0.2–2.0 V potential range. Three electrode methods were applied in all electrochemical studies. After immobilization process, the characterizations of the electro catalytic surfaces (Cs−CoL−Pt) were carried out by cyclic voltammetry and SEM images. The SEM images clearly indicated that the [CoL] complex is immobilized onto composite films. The electrocatalytic activity of the modified electrodes on the catechol was investigated using buffer solutions of different pH values. The results of catalytic studies revealed that, pH=10 buffer solution was the optimal solution and 1 : 1 Cs−CoL−Pt electrode was the best electrode for catechol oxidation. In square wave voltammetry measurements using this electrode, two linear working ranges were determined. The linear response ranges for catechol determination were found as 3.0 μM–6.0 μM and 16 μM–80 μM for the first and the second linear working ranges, respectively, with 1.1 μM detection limit.     

Recovering platinum from wastewater by charring biofilm of microbial fuel cells (MFCs)

Reduction in and recovery of precious metals are research hotspots in the environmental engineering field. In this study, we investigated the transformation and distribution of platinum in microbial fuel cells (MFCs) and demonstrated a feasible approach to recover platinum (Pt) from wastewater with less than 16.88?mg/L platinum through charring biofilms in MFCs and generate Pt/C catalyst. The optimal reaction condition was identified, and charred biofilms were analyzed via SEM-EDS, XRD and XPS. Results showed that less than 10% of Pt was in MFC effluents, and less than 0.5% was in the cathode chamber when the influent concentration was below 16.88?mg/L. Close to 40% of Pt could be recovered. The recovery efficiency could be higher should the reactions run longer. SEM-EDS and XRD results indicated that the metallic form Pt⁰ is one of the reduction products in MFCs. XPS results induced that Pt (IV) was reduced to Pt (II) and Pt⁰.     

Pt(II) complexes immobilized on polymer‐modified magnetic carbon nanotubes as a new platinum drug delivery system

We combine nanotechnology and chemical synthesis to create a novel multifunctional platinum drug delivery vehicle based on magnetic carbon nanotubes (multiwall carbon nanotubes/Fe₃O₄@poly(citric acid)/cis‐[(Pt(1,7‐phenanthroline)(DMSO)Cl₂)]‐b‐poly(ethylene glycol) (MCNTs/FO@PC/Pt(II)‐b‐PEG)) for targeted cancer therapy. MCNTs/FO@PC/Pt(II)‐b‐PEG was conveniently prepared by conjugating cis‐[Pt(1,7‐phenanthroline)(DMSO)Cl₂] complex to MCNTs/FO@PC‐b‐PEG via strong hydrogen‐bonding interactions. In comparison with free cisplatin and Pt(II) complex, MCNTs/FO@PC/Pt(II)‐b‐PEG shows higher solubility in aqueous solution and higher cytotoxicity towards human cervical cancer HeLa cells and human breast cancer MDA‐MB‐231 cells. In vitro release experiments revealed that the platinum drug‐loaded delivery system is relatively stable under physiological conditions (pH = 7.4 and 37 °C) but susceptible to acidic environments (pH = 5.6 and 37 °C) which would trigger the release of loaded drugs. Fluorescence microscopy studies revealed that this magnetic nanohybrid system possesses marked cell‐specific targeting in vitro in the presence of an external magnetic field. The results indicated that the prepared superparamagnetic MCNTs/FO@PC/Pt(II)‐b‐PEG nanohybrid system is a promising candidate for inhibiting the proliferation of cancer cells.     

Design and Characterization of Maltoheptaose-b-Polystyrene Nanoparticles,as a Potential New Nanocarrier for Oral Delivery of Tamoxifen

Tamoxifen citrate (TMC), a non-steroidal antiestrogen drug used for the treatment of breast cancer, was loaded in a block copolymer of maltoheptaose-b-polystyrene (MH-b-PS) nanoparticles, a potential drug delivery system to optimize oral chemotherapy. The nanoparticles were obtained from self-assembly of MH-b-PS using the standard and reverse nanoprecipitation methods. The MH-b-PS@TMC nanoparticles were characterized by their physicochemical properties, morphology, drug loading and encapsulation efficiency, and release kinetic profile in simulated intestinal fluid (pH 7.4). Finally, their cytotoxicity towards the human breast carcinoma MCF-7 cell line was assessed. The standard nanoprecipitation method proved to be more efficient than reverse nanoprecipitation to produce nanoparticles with small size and narrow particle size distribution. Moreover, tamoxifen-loaded nanoparticles displayed spherical morphology, a positive zeta potential and high drug content (238.6 ± 6.8 µg mL⁻¹) and encapsulation efficiency (80.9 ± 0.4 %). In vitro drug release kinetics showed a burst release at early time points, followed by a sustained release profile controlled by diffusion. MH-b-PS@TMC nanoparticles showed higher cytotoxicity towards MCF-7 cells than free tamoxifen citrate, confirming their effectiveness as a delivery system for administration of lipophilic anticancer drugs.     

Human Serum Albumin Conjugated Nanoparticles for pH and Redox‐Responsive Delivery of a Prodrug of Cisplatin

Platinum anticancer drugs are particularly in need of controlled drug delivery because of their severe side effects. Platinum(IV) agents are designed as prodrugs to reduce the side effects of platinum(II) drugs; however, premature reduction could limit the effect as a prodrug. In this work, a highly biocompatible, pH and redox dual‐responsive delivery system is prepared by using hybrid nanoparticles of human serum albumin (HSA) and calcium phosphate (CaP) for the Pt^IV prodrug of cisplatin. This conjugate is very stable under extracellular conditions, so that it protects the platinum(IV) prodrug in HSA. Upon reaching the acidic and hypoxic environment, the platinum drug is released in its active form and is able to bind to the target DNA. The Pt–HSA/CaP hybrid inhibits the proliferation of various cancer cells more efficiently than cisplatin. Different cell cycle arrests suggest different cellular responses of the Pt^IV prodrug in the CaP nanocarrier. Interestingly, this delivery system demonstrates enhanced cytotoxicity to tumor cells, but not to normal cells.     

Tunable catalytic tubular micro-pumps operating at low concentrations of hydrogen peroxide

Catalytic micropumps consisting of Ti/Cr/Pt microtubes with diameters of 5-10 μm and tunable lengths in the range of 20-1000 μm are reported. Micropumps were fabricated by rolling up metallic nanomembranes into microtubes with an inner platinum layer. When immersed into a solution of hydrogen peroxide, the micropumps are activated by the catalytic decomposition of peroxide into oxygen microbubbles and water. Fluid pumping is demonstrated by the movement of polystyrene particles with a diameter of 1 μm through the catalytic microtubes. Concentrations from 0.009 to 11% H(2)O(2) were employed to study the catalytic generation of microbubbles in micropumps with different lengths. A minimum concentration of 0.06% fuel was determined to be sufficient to actuate the micropumps. Such devices based on rolled-up nanomembranes hold great promise for the integration into Lab-on-a-chip systems for sensing, sorting of particles and drug delivery.     

Luminescent platinum(ii) complexes with self-assembly and anti-cancer properties: hydrogel,pH dependent emission color and sustained-release properties under physiological conditions

Supramolecular interactions are of paramount importance in biology and chemistry, and can be used to develop new vehicles for drug delivery. Recently, there is a surge of interest on self-assembled functional supramolecular structures driven by intermolecular metal–metal interactions in cellular conditions. Herein we report a series of luminescent Pt(ii) complexes [Pt(C^N^N^pyr)(CNR)]⁺ [HC^N^N^pyr = 2-phenyl-6-(1H-pyrazol-3-yl)-pyridine)] containing pincer type ligands having pyrazole moieties. These Pt(ii) complexes exert potent cytotoxicity to a panel of cancer cell lines including primary bladder cancer cells and display strong phosphorescence that is highly sensitive to the local environment. The self-assembly of these complexes is significantly affected by pH of the solution medium. Based on TEM, SEM, ESI-MS, absorption and emission spectroscopy, and fluorescence microscopy together with cell based assays, [Pt(C^N^N^pyr)(CNR)]⁺ complexes were observed to self-assemble into orange phosphorescent polymeric aggregates driven by intermolecular Pt(ii)–Pt(ii) and ligand–ligand interactions in a low-pH physiological medium. Importantly, the intracellular assembly and dis-assembly of [Pt(C^N^N^pyr)(CNR)]⁺ are accompanied by change of emission color from orange to green. These [Pt(C^N^N^pyr)(CNR)]⁺ complexes accumulated in the lysosomes of cancer cells, increased the lysosomal membrane permeability and induced cell death. One of these platinum(ii) complexes formed hydrogels which displayed pH-responsive and sustained release properties, leading to low-pH-stimulated and time-dependent cytotoxicity towards cancer cells. These hydrogels can function as vehicles to deliver anti-cancer agent cargo, such as the bioactive natural products studied in this work.     

Platinum(II), palladium(II), nickel(II), and gold(I) complexes of the “electrospray-friendly” thiolate ligands 4-SC5H4N− and 4-SC6H4OMe−

The series of platinum(II), palladium(II), and nickel(II) complexes [ML₂(dppe)] [M = Ni, Pd, Pt; L = 4–SC₅H₄N or 4–SC₆H₄OMe; dppe = Ph₂PCH₂CH₂PPh₂] containing pyridine-4-thiolate or 4-methoxybenzenethiolate ligands, together with the corresponding gold(I) complexes [AuL(PPh₃)], were prepared and their electrospray ionization mass spectrometric behavior compared with that of the thiophenolate complexes [M(SPh)₂(dppe)] (M = Ni, Pd, Pt) and [Au(SPh)(PPh₃)]. While the pyridine-4-thiolate complexes yielded protonated ions of the type [M + H]⁺ and [M + 2H]²⁺ ions in the Ni, Pd, and Pt complexes, an [M + H]⁺ ion was only observed for the platinum derivative of 4-methoxybenzenethiolate. Other ions, which dominated the spectra of the thiophenolate complexes, were formed by thiolate loss and aggregate formation. The X-ray crystal structure of [Pt(SC₆H₄OMe–4)₂(dppe)] is also reported.     

Synthesis,characterization, crystal structure and antiproliferative activity of platinum(II) complexes with 2-acetylpyridine-4-cyclohexyl-thiosemicarbazone

New platinum complexes have been synthesized by the reaction of Na₂PtCl₄ with 2-acetylpyridine-4-cyclohexyl-thiosemicarbazone, HAc4CyclHexyl (1). The new complexes [Pt(Ac4CyclHexyl)Cl] (2) and [Pt(Ac4CyclHexyl)₂] (3) have been characterized by elemental analyses and spectroscopic studies. The crystal structure of the complex [Pt(Ac4CyclHexyl)Cl] · DMF has been solved by single-crystal X-ray diffraction. The anion of Ac4CyclHexyl coordinates in a planar conformation to the central platinum(II) through the pyridyl N, azomethine N and thiolato S atoms. The crystal packing is determined by double intermolecular hydrogen interactions, π–π, Pt–C and Pt–π contacts. The cytotoxic activities of 1–3 have been evaluated for antiproliferative activity in vitro against the cells of three human cancer cell lines: MCF-7 (human breast cancer cell line), T24 (bladder cancer cell line), A-549 (non-small cell lung carcinoma) and a mouse L-929 (a fibroblast-like cell line cloned from strain L). The compounds 1–3 display IC₅₀ values in a μM range better than that of the antitumor drug cisplatin and are considered as agents with potential antitumor activity candidates for further stages of screening in vitro and/or in vivo.     

Let-7i miRNA and platinum loaded nano-graphene oxide platform for detection/reversion of drug resistance and synergetic chemical-photothermal inhibition of cancer cell

The drug resistance of chemotherapy is a major challenge to overcome for antineoplastic agents and the reverse of drug resistant is essential for cancer therapy. Herein, we developed a drug delivery system which can simultaneously detect/reverse the drug resistance and perform synergetic treatment of cancer. In this work, we integrated cyanine5(Cy5) modified mi RNA(let-7 i)(Cy5-mi RNA) and platinum onto nano-graphene oxide(NGO)(30-50 nm) platform to achieve simultaneously detection/reversion of ...     

Redox-responsive phenyl-functionalized polylactide micelles for enhancing Ru complexes delivery and phototherapy

Poly(ethylene glycol)-poly(lactic acid) block copolymer (PEG-PLA) is one of the most widely used biomedical polymers in clinical drug delivery owing to its biocompatibility and biodegradability. However, endowing PEG-PLA micelles with high drug loading, self-assembly stability and fast intracellular drug release is still challenging. Redox-responsive diblock copolymers (MPEG-SS-PMLA) of poly(ethylene glycol) and phenyl-functionalized poly(lactic acid) with disulfide bond as the linker are synthesized to prepare PLA-based micelles that demonstrate excellent colloidal stability and high Ru loading. Notably, MPEG-SS-PMLA achieved a remarkably high Ru loading efficiency of 84.3% due to the existence of strong π-π stacking between phenyl and Ru complex. MPEG-SS-PMLA exhibited good colloidal stability in physiological condition but quickly destabilized by reductive tumor microenvironment. Interestingly, about 74% of Ru complex was released under 10 mmol/L GSH concentration. Ru-loaded MEPG-SS-PMLA showed efficient delivery and release of Ru complex into MCF-7 cancer cells, achieving enhanced in vitro and in vivo antitumor activity of photodynamic therapy. This feasible functionalization method of MPEG-PLA has appeared to be a clinically viable platform for controlled delivery therapeutic agents and enhanced phototherapy.     

Advances in Platinum Chemotherapeutics

The approved platinum(II)‐based anticancer agents cisplatin, carboplatin and oxaliplatin are widely utilised in the clinic, although with numerous disadvantages. With the aim of circumventing unwanted side‐effects, a great deal of research is being conducted in the areas of cancer‐specific targeting, drug administration and drug delivery. The targeting of platinum complexes to cancerous tissues can be achieved by the attachment of small molecules with biological significance. In addition, the administration of platinum complexes in the form of platinum(IV) allows for intracellular reduction to release the active form of the drug, cisplatin. Drug delivery includes such technologies as liposomes, dendrimers, polymers and nanotubes, with all showing promise for the delivery of platinum compounds. In this paper we highlight some of the recent advances in the field of platinum chemotherapeutics, with a focus on the technologies that attempt to utilise the cytotoxic nature of cisplatin, whilst improving drug targeting to reduce side‐effects.     

Synthesis, structural characterization, and photophysical properties of palladium and platinum(II) complexes containing 7,8-benzoquinolinate and various phosphine ligands

A series of mononuclear cyclometalated benzo[h]quinolinate platinum and palladium(II) complexes with phosphine ligands, namely, [M(bzq)ClL] (L=PPh2H, Pt 1, Pd 2; PPh2CCPh, Pt 3, Pd 4), [Pt(bzq)(PPh2H)(PPh2CCPh)]ClO4 5, [Pt(bzq)(PPh2C(Ph)=C(H)PPh2)]ClO4 6, and [Pt(bzq)(CCPh)(PPh2CCPh)] (7a, 7b), were synthesized. The X-ray crystal structures of 1, 6.CH3COCH3.1/2CH3(CH2)4CH3, and 7b.CH3COCH3 have been determined. In 1, the metalated carbon atom and the P atom are mutually cis, whereas in 7b they are trans located. For complex 6, C and N are crystallographically indistinguishable. Reaction of [Pt(bzq)(mu-Cl)]2 with PPh2H and excess of NEt3 leads to the phosphide-bridge platinum dimer [Pt(bzq)(mu-PPh2)]2 8 (X-ray). Moderate pi-pi intermolecular interactions and no evident Pt-Pt interactions are found in 1, 7b, and in 8. All of the complexes exhibit absorption bands at high energy due to the intraligand transitions (1IL pi --> pi) and absorptions at lower energy which are attributed to MLCT (5d) pi --> pi (CLambdaN) transition. Platinum complexes show strong luminescence in both solid state and frozen solutions. The influence of the coligands on the photophysics of the platinum complexes has been examined by absorption and emission spectroscopy.     

Palladium(II) and platinum(II) organometallic complexes with the model nucleobase anions of thymine, uracil, and cytosine: antitumor activity and interactions with DNA of the platinum compounds

Pd(II) and Pt(II) complexes with the anions of the model nucleobases 1-methylthymine (1-MethyH), 1-methyluracil (1-MeuraH), and 1-methylcytosine (1-MecytH) of the types [Pd(dmba)(mu-L)]2 [dmba = N,C-chelating 2-((dimethylamino)methyl)phenyl; L = 1-Methy, 1-Meura or 1-Mecyt] and [M(dmba)(L)(L')] [L = 1-Methy or 1-Meura; L' = PPh(3) (M = Pd or Pt), DMSO (M = Pt)] have been obtained. Palladium complexes of the types [Pd(C6F5)(N-N)(L)] [L = 1-Methy or 1-Meura; N-N = N,N,N',N'-tetramethylethylenediamine (tmeda), 2,2'-bipyridine (bpy), or 4,4'-dimethyl-2,2'-bipyridine (Me2bpy)] and [NBu4][Pd(C6F5)(1-Methy)2(H2O)] have also been prepared. The crystal structures of [Pd(dmba)(mu-1-Methy)]2, [Pd(dmba)(mu-1-Mecyt)]2.2CHCl3, [Pd(dmba)(1-Methy)(PPh3)].3CHCl3, [Pt(dmba)(1-Methy)(PPh3)], [Pd(tmeda)(C6F5)(1-Methy)], and [NBu4][Pd(C6F5)(1-Methy)2(H2O)].H2O have been established by X-ray diffraction. The DNA adduct formation of the new platinum complexes synthesized was followed by circular dichroism and electrophoretic mobility. Atomic force microscopy images of the modifications caused by the platinum complexes on plasmid DNA pBR322 were also obtained. Values of IC50 were also calculated for the new platinum complexes against the tumor cell line HL-60. All the new platinum complexes were more active than cisplatin (up to 20-fold in some cases).     

Platinum(II) and Palladium(II) Bis(chelate) Complexes Containing both Tri(1‐cyclohepta‐2, 4, 6‐trienyl)phosphane,P(C7H7)3, and Dichalcogenolato Ligands

Tri(1‐cyclohepta‐2, 4, 6‐trienyl)phosphane, P(C₇H₇)₃ ([P] when coordinated to a metal atom), was used to stabilize complexes of platinum(II) and palladium(II) with chelating dichalcogenolato ligands as [P]M(E∩E) [E = S, ∩ = CH₂CH₂, M = Pt ( 3a ); E = S, ∩ = 1, 2‐C₆H₄, M = Pt ( 5a ), Pd ( 6a ); E = S, ∩ = C(O)C(O), M = Pt ( 7a ), Pd ( 8a ); E = S, Se, ∩ = 1, 2‐C₂(B₁₀H₁₀), M = Pt ( 9a, 9b ), Pd ( 10a, 10b ); E = S, ∩ = Fe₂(CO)₆, M = Pt ( 11a ), Pd ( 12a )]. Starting materials in all reactions were [P]MCl₂ with M = Pt ( 1 ) and Pd ( 2 ). Attempts at the synthesis of [P]M(ER)₂ with non‐chelating chalcogenolato ligands were not successful. All new complexes were characterized by multinuclear magnetic resonance spectroscopy in solution (¹H, ¹³C, ³¹P, ⁷⁷Se and ¹⁹⁵Pt NMR), and the molecular structures of 5a and 12a were determined by X‐ray analysis. Both in the solid state and in solution the ligand [P] is linked to the metal atom by the P‐M bond and by η²‐C=C coordination of the central C=C bond of one of the C₇H₇ rings. In solution, intramolecular exchange between coordinated and non‐coordinated C₇H₇ rings is observed, the exchange process being markedly faster in the case of M = Pd than for M = Pt.     

Targeted single-wall carbon nanotube-mediated Pt(IV) prodrug delivery using folate as a homing device

Most low-molecular-weight platinum anticancer drugs have short blood circulation times that are reflected in their reduced tumor uptake and intracellular DNA binding. A platinum(IV) complex of the formula c, c, t-[Pt(NH 3) 2Cl 2(O 2CCH 2CH 2CO 2H)(O 2CCH 2CH 2CONH-PEG-FA)] ( 1), containing a folate derivative (FA) at an axial position, was prepared and characterized. Folic acid offers a means of targeting human cells that highly overexpress the folate receptor (FR). Compound 1 was attached to the surface of an amine-functionalized single-walled carbon nanotube (SWNT-PL-PEG-NH 2) through multiple amide linkages to use the SWNTs as a "longboat delivery system" for the platinum warhead, carrying it to the tumor cell and releasing cisplatin upon intracellular reduction of Pt(IV) to Pt(II). The ability of SWNT tethered 1 to destroy selectively FR(+) vs FR(-) cells demonstrated its ability to target tumor cells that overexpress the FR on their surface. That the SWNTs deliver the folate-bearing Pt(IV) cargos into FR(+) cancer cells by endocytosis was demonstrated by the localization of fluorophore-labeled SWNTs using fluorescence microscopy. Once inside the cell, cisplatin, formed upon reductive release from the longboat oars, enters the nucleus and reacts with its target nuclear DNA, as determined by platinum atomic absorption spectroscopy of cell extracts. Formation of the major cisplatin 1,2-intrastrand d(GpG) cross-links on the nuclear DNA was demonstrated by use of a monoclonal antibody specific for this adduct. The SWNT-tethered compound 1 is the first construct in which both the targeting and delivery moieties have been incorporated into the same molecule; it is also the first demonstration that intracellular reduction of a Pt(IV) prodrug leads to the cis-{Pt((NH 3) 2} 1,2-intrastrand d(GpG) cross-link in nuclear DNA.     

NIR-triggered drug delivery system based on phospholipid coated ordered mesoporous carbon for synergistic chemo-photothermal therapy of cancer cells

Chemo-photothermal treatment is one of the most efficient strategies for cancer therapy. However, traditional drug carriers without near-infrared absorption capacity need to be loaded with materials behaving photothermal properties, as it results in complicated synthesis process, inefficient photothermal effects and hindered NIR-mediated drug release. Herein we report a facile synthesis of a polyethylene glycol (PEG) linked liposome (PEG-liposomes) coated doxorubicin (DOX)-loaded ordered mesoporous carbon (OMC) nanocomponents (PEG-LIP@OMC/DOX) by simply sonicating DOX and OMC in PEG-liposomes suspensions. The as-obtained PEG-LIP@OMC/DOX exhibits a nanoscale size (600±15 nm), a negative surface potential (-36.70 mV), high drug loading (131.590 mg/g OMC), and excellent photothermal properties. The PEG-LIP@OMC/DOX can deliver loaded DOX to human MCF-7 breast cancer cells (MCF-7) and the cell toxicity viability shows that DOX unloaded PEG-LIP@OMC has no cytotoxicity, confirming the PEG-LIP@OMC itself has excellent biocompatibility. The NIR-triggered release studies demonstrate that this NIR-responsive drug delivery system enables on-demand drug release. Furthermore, cell viability results using human MCF-7 cells demonstrated that the combination of NIR-based hyperthermal therapy and triggered chemotherapy can provide higher therapeutic efficacy than respective monotherapies. With these excellent features, we believe that this phospholipid coating based multifunctional delivery system strategy should promote the application of OMC in nanomedical applications.     

NIR-triggered drug delivery system based on phospholipid coated ordered mesoporous carbon for synergistic chemo-photothermal therapy of cancer cells

Chemo-photothermal treatment is one of the most efficient strategies for cancer therapy. However, traditional drug carriers without near-infrared absorption capacity need to be loaded with materials behaving photothermal properties, as it results in complicated synthesis process, inefficient photothermal effects and hindered NIR-mediated drug release. Herein we report a facile synthesis of a polyethylene glycol (PEG) linked liposome (PEG-liposomes) coated doxorubicin (DOX)-loaded ordered mesoporous carbon (OMC) nanocomponents (PEG-LIP@OMC/DOX) by simply sonicating DOX and OMC in PEG-liposomes suspensions. The as-obtained PEG-LIP@OMC/DOX exhibits a nanoscale size (600 ± 15 nm), a negative surface potential (−36.70 mV), high drug loading (131.590 mg/g OMC), and excellent photothermal properties. The PEG-LIP@OMC/DOX can deliver loaded DOX to human MCF-7 breast cancer cells (MCF-7) and the cell toxicity viability shows that DOX unloaded PEG-LIP@OMC has no cytotoxicity, confirming the PEG-LIP@OMC itself has excellent biocompatibility. The NIR-triggered release studies demonstrate that this NIR-responsive drug delivery system enables on-demand drug release. Furthermore, cell viability results using human MCF-7 cells demonstrated that the combination of NIR-based hyperthermal therapy and triggered chemotherapy can provide higher therapeutic efficacy than respective monotherapies. With these excellent features, we believe that this phospholipid coating based multifunctional delivery system strategy should promote the application of OMC in nanomedical applications.