RESUMEN

Graft copolymers have unique application scenarios in the field of high-performance thermoplastic elastomers, resins and rubbers. ß-myrcene (My) is a biomass monomer derived from renewable plant resources, and its homopolymer has a low glass transition temperature and high elasticity. In this work, a series of tapered copolymers P(My-co-AMS)k (k = 1, 2, 3) were first synthesized in cyclohexane by one-pot anionic polymerization of My and α-methyl styrene (AMS) using sec-BuLi as the initiator. PAMS chain would fracture when heated at high temperature and could endow the copolymer with thermal degradation property. The effect of the incorporation of AMS unit on the thermal stability and glass transition temperature of polymyrcene main chain was studied. Subsequently, the double bonds in the linear copolymers were partially epoxidized and hydroxylated into hydroxyl groups to obtain hydroxylated copolymer, which was finally used to initiate the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) to synthesize the graft copolymer with PCL as the side chain. All these copolymers before and after modifications were characterized by proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), thermogravimetry analysis (TGA), and differential scanning calorimeter (DSC).

RESUMEN

Anticancer drugs used for systemic chemotherapy often exhibit off-target toxicity and uncontrolled drug release due to their lack of targeting. To improve the bioavailability of drugs and reduce side effects, we have developed a mixed micelle of nanomedicine composed of two prodrugs with surface modified monoclonal antibody for cancer therapy. In this system, Nimotuzumab was used as targeting ligands of the mixed micelles (named as DCMMs) that is composed of polymer-doxorubicin prodrug (abbreviated as PEG-b-P(GMA-ss-DOX)) and maleimide polyethylene glycol-chlorin e6 (abbreviated as Mal-PEG-Ce6). The mixed micelles modified with Nimotuzumab (named as NTZ-DCMMs) bind to overexpressed EGFR receptors on Hepatoma-22 (H22) cells. Disulfide bonds in PEG-b-P(GMA-ss-DOX) are disrupted in tumor microenvironment, inducing the reduction-responsive release of DOX and leading to tumor cell apoptosis. Simultaneously, Chlorin e6 (Ce6) produced plenty of singlet oxygen (1O2) under laser irradiation to kill tumor cells. In vivo biological distribution and antineoplastic effect experiments demonstrate that NTZ-DCMMs enhanced drug enrichment at tumor sites through targeting function of antibody, dramatically suppressing tumor growth and mitigating cardiotoxicity of drugs. All results prove that NTZ-DCMMs have the ability to actively target H22 cells and quickly respond to tumor microenvironment, which is expected to become an intelligent and multifunctional drug delivery carrier for efficient chemotherapy and photodynamic therapy of hepatoma. STATEMENT OF SIGNIFICANCE: Anticancer drugs used for systemic chemotherapy often exhibit off-target toxicity due to their lack of targeting. Therefore, it's necessary to develop effective, targeted, and collaborative treatment strategies. We construct a mixed micelle of nanomedicine based on two polymer prodrugs and modified with monoclonal antibody on surface for cancer therapy. Under the tumor cell microenvironment, the disulfide bonds of polymer-ss-DOX were broken, effectively triggering DOX release. The photosensitizer Ce6 could generate a large amount of ROS under light, which synergistically promotes tumor cell apoptosis. By coupling antibodies to the hydrophilic segments of polymer micelles, drugs can be specifically delivered. Compared with monotherapy, the combination of chemotherapy and photodynamic therapy can significantly enhance the therapeutic effect of liver cancer.

Asunto(s)

Clorofilidas , Doxorrubicina , Micelas , Nanomedicina , Fotoquimioterapia , Porfirinas , Profármacos , Profármacos/farmacología , Profármacos/química , Profármacos/farmacocinética , Doxorrubicina/farmacología , Doxorrubicina/química , Animales , Fotoquimioterapia/métodos , Línea Celular Tumoral , Nanomedicina/métodos , Porfirinas/química , Porfirinas/farmacología , Porfirinas/farmacocinética , Humanos , Antineoplásicos/farmacología , Antineoplásicos/química , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/farmacocinética , Ratones , Polímeros/química , Polímeros/farmacología , Ratones Endogámicos BALB C , Polietilenglicoles/química , Polietilenglicoles/farmacología , Apoptosis/efectos de los fármacos

RESUMEN

Stimuli-responsive cross-linked micelles (SCMs) are ideal nanocarriers for anti-cancer drugs. Compared with non-cross-linked micelles, SCMs exhibit superior structural stability. At the same time, the introduction of an environmentally sensitive crosslinker into a drug delivery system allows SCMs to respond to single or multiple stimuli in the tumor microenvironment, which can minimize drug leakage during the blood circulation process. In this study, curcumin (CUR) was modified as the hydrophobic core crosslinker by utilizing the bisphenol structure, and redox sensitive disulfide bonds were introduced to prepare the glutathione (GSH) stimulated responsive core crosslinker (abbreviated as N3-ss-CUR-ss-N3). In addition, amphiphilic polymer APEG-b-PBYP was prepared through the ring opening reaction, and reacted with the crosslinker through the "click" reaction. After being dispersed in the aqueous phase, core cross-linked nanoparticles (CCL NPs) were obtained. Finally, monoclonal antibody CD326 (mAb-CD326) was reduced and coupled to the hydrophilic chain ends to obtain the nanoparticles with surface modified antibodies (R-mAb-CD326@CCL NPs) for further enhancing targeted drug delivery. The structures of the polymer and crosslinker were characterized by 1H NMR, UV-Vis, FT-IR, and GPC. The morphology, size and stability of CCL NPs and R-mAb-CD326@CCL NPs were investigated by DLS and TEM. The in vitro drug release behavior of CCL NPs was also studied. The results showed that the CCL NPs exhibited reduction-responsiveness and were able to release the original drug CUR under 10 mM GSH conditions. Additionally, the CCL NPs exhibited excellent stability in both the simulated body fluid environment and organic solvents. Especially, R-mAb-CD326@CCL NPs can actively target tumor cells and showed better therapeutic efficacy in in vivo experiments with a tumor suppression rate of 78.7%. This work provides a new idea for the design of nano-drugs targeting breast cancer.

Asunto(s)

Curcumina , Neoplasias , Profármacos , Profármacos/química , Curcumina/química , Micelas , Anticuerpos Monoclonales/uso terapéutico , Espectroscopía Infrarroja por Transformada de Fourier , Polímeros/química , Neoplasias/tratamiento farmacológico

RESUMEN

An ionic conductive elastomer with good comprehensive properties is constructed from a ternary polymerizable deep eutectic solvent (PDES) containing choline chloride, acrylic acid and itaconic acid (IA). The IA component is found to boost the synergetic hydrogen bonds and greatly improve the mechanical strength of elastomer.

RESUMEN

Antibody-drug conjugates (ADCs) are a class of tumor cell-targeting drugs that have developed rapidly in recent years. From the perspective of further improving ADC targeting and developing natural macromolecules as drug carriers, it is still challenging and necessary to try new targeted drug delivery modalities. In this study, we have developed an antibody-modified prodrug nanoparticle based on biomacromolecule dextran (DEX) to delivery antitumour drug doxorubicin (DOX). Firstly, oxidized dextran (ODEX) and DOX were bonded to yield ODEX-DOX via Schiff base reaction, which can self-assemble into nanoparticles (NPs) carrying some aldehyde groups. Subsequently, the amino groups of CD147 monoclonal antibody were bound to the aldehyde groups on the surface of ODEX-DOX NPs, resulting in acid-responsive and antibody-modified CD147-ODEX-DOX NPs with relatively small particle size and high DOX loading. FT-IR, UV-Vis, HPLC, and 1H NMR were used to demonstrate the successful synthesis of polymer prodrug ODEX-DOX NPs and antibody-modified nanomedicine CD147-ODEX-DOX NPs. Dynamic light scattering (DLS) was used to evaluate the stability and the pH responsiveness of ODEX-DOX NPs in different media and tumour microenvironment. The in vitro total release content of DOX reached approximately 70% in PB 5.0 buffer solution after 103 h. Furthermore, the in vivo antitumour efficacy and biodistribution experiments confirmed that CD147-ODEX-DOX NPs could significantly inhibit the growth of HepG2 tumour. All of the results indicate that this acid-sensitive nanomedicine has higher safety and targeting effects. It promises to be an ideal strategy for future targeted drug delivery systems and anticancer therapies.

Asunto(s)

Carcinoma Hepatocelular , Neoplasias Hepáticas , Nanopartículas , Profármacos , Humanos , Profármacos/química , Dextranos , Anticuerpos Monoclonales , Espectroscopía Infrarroja por Transformada de Fourier , Distribución Tisular , Sistemas de Liberación de Medicamentos/métodos , Doxorrubicina/química , Nanopartículas/química , Neoplasias Hepáticas/tratamiento farmacológico , Concentración de Iones de Hidrógeno , Microambiente Tumoral

RESUMEN

A new polymerizable and dynamic deep eutectic solvent (DES) consisting of choline chloride and α-lipoic acid is proposed. By virtue of thermally-initiated ring-opening polymerization (ROP) of cyclic disulfide and multiple dynamic interactions (disulfide, hydrogen, and coordination bonds), multifunctional ionogels with good comprehensive properties are developed and explored as potential flexible conductors.

Asunto(s)

Colina , Disolventes Eutécticos Profundos , Solventes/química , Colina/química , Disulfuros

RESUMEN

Traditional wound dressings have poor mechanical properties and a single function, which cannot achieve rapid healing of diabetic wounds in a unique physiological microenvironment. In order to develop multifunctional hydrogel dressings with appropriate biological activity to accelerate wound healing and obtain better clinical therapeutic effects, herein we report a hybrid system based on drug loaded mesoporous silica and injectable polymer hydrogels mixed with hypoglycemic drug metformin (Met) as a dressing for diabetic wounds. Firstly, a copolymer with the phenylboronic acid group in the side group, poly(acrylamide-co-dimethylaminopropylacrylamide-co-methacrylamidophenylboronic acid) (abbreviated as PB), was prepared. PB was mixed with polyvinyl alcohol (PVA) to obtain an injectable hydrogel (named PP) with pH/glucose dual responsiveness, which was formed through the combination of the phenylborate group of PB and o-diol of PVA. In another reaction, polydopamine-modified mesoporous silica nanoparticles (MSN@PDA) were prepared and used to adsorb antibiotic tetracycline hydrochloride (TH) to obtain drug-loaded MSN@PDA-TH nanoparticles. Subsequently, the hybrid hydrogel dressing (abbreviated as PP/MSN@PDA-TH/Met) was obtained by mixing PB, PVA, Met and MSN@PDA-TH. The self-healing, rheological and adhesive properties of the hybrid hydrogel were characterized. The results show that the hydrogel dressing has good physical properties. Met and TH were released in vitro in different pH media and glucose environments. The results show that the hydrogel dressing has dual responsiveness towards pH and glucose, and can continuously release metformin and tetracycline, which is conducive to accelerating wound healing. The antimicrobial activity, ROS clearance ability and biocompatibility of the hydrogel dressing were evaluated. The results indicate that the hydrogel dressing was multifunctional. Finally, a full-thickness wound repair model of diabetic mice induced by streptozotocin (STZ) was established. The hybrid hydrogel dressing was applied to the wound surface of mice. The wound healing testing on diabetic mice confirmed that the wound covered with the hybrid hydrogel dressing was completely healed with the formation of the new skin and hair within 9 days to 12 days. Histological analysis indicates that, compared to the PBS control, the hydrogel dressing did not cause significant inflammation in the wound, and a large number of blood vessels, glands and hair follicles appeared. This study provides a good strategy for multi-drug synergistic treatment of diabetic foot ulcers.

Asunto(s)

Pie Diabético , Cicatrización de Heridas , Masculino , Animales , Ratones , Ratones Endogámicos C57BL , Hidrogeles/química , Vendajes , Polímeros/química , Antioxidantes/química , Adhesivos/química

RESUMEN

Tumor-associated macrophages (TAMs)-based immunotherapy is a promising strategy. Since TAMs are mainly composed of M2-type macrophages, they have a promoting effect on tumor growth, invasion, and metastasis. M2-type macrophages contain a specific receptor CD163 on their surface, providing a prerequisite for active targeting to TAMs. In this study, we prepared CD163 monoclonal antibody modified doxorubicin-polymer prodrug nanoparticles (abbreviated as mAb-CD163-PDNPs) with pH responsiveness and targeted delivery. First, DOX was bonded with the aldehyde group of a copolymer by Schiff base reaction to form an amphiphilic polymer prodrug, which could self-assemble into nanoparticles in the aqueous solution. Then, mAb-CD163-PDNPs were generated through a "Click" reaction between the azide group on the surface of the prodrug nanoparticles and dibenzocyclocytyl-coupled CD163 monoclonal antibody (mAb-CD163-DBCO). The structure and assembly morphology of the prodrug and nanoparticles were characterized by 1H NMR, MALDI-TOF MS, FT-IR UV-vis spectroscopy, and dynamic light scattering (DLS). In vitro drug release behavior, cytotoxicity, and cell uptake were also investigated. The results show that the prodrug nanoparticles have regular morphology and stable structure, especially mAb-CD163-PDNPs, which can actively target TAMs at tumor sites, respond to the acidic environment in tumor cells, and release drugs. While depleting TAMs, mAb-CD163-PDNPs can actively enrich drugs at the tumor site and have a strong inhibitory effect on TAMs and tumor cells. The result of the in vivo test also shows a good therapeutic effect, with a tumor inhibition rate of 81%. This strategy of delivering anticancer drugs in TAMs provides a new way to develop targeted drugs for immunotherapy of malignant tumors.

RESUMEN

To overcome the limitation of conventional nanodrugs in tumor targeting efficiency, coupling targeting ligands to polymeric nanoparticles can enhance the specific binding of nanodrugs to tumors. Cyclo(Arg-Gly-Asp-d-Phe-Lys) (abbreviated as c(RGDfK)) peptide has been widely adopted due to its high affinity to the tumor marker αvß3 integrin receptor. In this study, we develop a cRGD peptide-conjugated camptothecin (CPT) prodrug, which enables self-assembly of nanoparticles for precise targeting and enrichment in tumor tissue. We first synthesized a camptothecin derivative (CPT-ss-N3) with a reduction-sensitive bond and simultaneously modified PEG to obtain cRGD-PEG-N3. After ring-opening polymerization of the 2-(but-3-yn-1-yolxy)-2-oxo-1,3,2-dioxaphospholane (BYP), an amphiphilic polymeric prodrug, referred to as cRGD-PEG-g-(PBYP-ss-CPT), was obtained via copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The self-assembly in buffer solution of the cRGD-functional prodrug was studied through DLS and TEM. The in vitro drug release behavior of cRGD-PEG-g-(PBYP-ss-CPT) nanoparticles was investigated. The results show that the nanoparticles are reduction-responsive and the bonded CPT can be released. Endocytosis and MTT assays demonstrate that the cRGD-conjugated prodrug has better affinity for tumor cells, accumulates more intracellularly, and is therefore, more effective. The in vivo drug metabolism studies show that nanoparticles greatly prolong the retention time in circulation. By monitoring drug distribution in tumor and in various tissues, we find that free CPT can be rapidly metabolized, resulting in low accumulation in all tissues. However, cRGD-PEG-g-(PBYP-ss-CPT) nanoparticles accumulate in tumor tissues in higher amounts than PEG-g-(PBYP-ss-CPT) nanoparticles, except for the inevitable capture by the liver. This indicates that the nanomedicine with cRGD has a certain targeting property, which can improve drug delivery efficiency.

RESUMEN

This work aims to construct biocompatible, biodegradable core-cross-linked and insulin-loaded nanoparticles which are sensitive to glucose and release insulin via cleavage of the nanoparticles in a high-concentration blood glucose environment. First, a polyphosphoester-based diblock copolymer (PBYP-g-Gluc)-b-PEEP was prepared via ring-opening copolymerization (ROP) and the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) in which PBYP and PEEP represent the polymer segments from 2-(but-3-yn-1-yloxy)-2-oxo-1,3,2-dioxaphospholane and 2-ethoxy-2-oxo-1,3,2-dioxaphospholane, respectively, and Gluc comes from 2-azidoethyl-ß-d-glucopyranoside (Gluc-N3) that grafted with PBYP. The structure and molecular weight of the copolymer were characterized by 1H NMR, 31P NMR, GPC, FT-IR, and UV-vis measurements. The amphiphilic copolymer could self-assemble into core-shell uncore-cross-linked nanoparticles (UCCL NPs) in aqueous solutions and form core-cross-linked nanoparticles (CCL NPs) after adding cross-linking agent adipoylamidophenylboronic acid (AAPBA). Dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to study the self-assembly behavior of the two kinds of NPs and the effect of different Gluc group contents on the size of NPs further to verify the stability and glucose sensitivity of CCL NPs. The ability of NPs to load fluorescein isothiocyanate-labeled insulin (FITC-insulin) and their glucose-triggered release behavior were detected by a fluorescence spectrophotometer. The results of methyl thiazolyl tetrazolium (MTT) assay and hemolysis activity experiments showed that the CCL NPs had good biocompatibility. An in vivo hypoglycemic study has shown that FITC-insulin-loaded CCL NPs could reduce blood glucose and have a protective effect on hypoglycemia. This research provides a new method for constructing biodegradable and glucose-sensitive core-cross-linked nanomedicine carriers for controlled insulin release.

Asunto(s)

Glucosa , Nanopartículas , Fluoresceína-5-Isotiocianato/análogos & derivados , Insulina/análogos & derivados , Espectroscopía Infrarroja por Transformada de Fourier

RESUMEN

In the treatment of tumor-targeted small-molecule anti-cancer drugs, antibody-mediated therapies, especially for antibody-drug conjugates (ADCs), have revealed great latent force. However, the therapeutic drugs provided by ADCs possess limitation. Considering that the combination of antibodies and nano-drugs can broaden their applicability in the field of tumor treatment, herein, we developed an antibody conjugated polymeric prodrug nanoparticles SAE-PEG-b-PBYP-ss-CPT for targeted camptothecin (CPT) delivery to liver tumor cells. The diblock copolymer was composed of PEG and biodegradable polyphosphoester (PBYP) containing alkynyl groups in the side chain. A derivative of CPT (CPT-ss-N3) was bonded to the PBYP via "click" reaction. The diethyl squarate (SAE) in the terminal of PEG chain was used as a functional group to bond with CD147 monoclonal antibody (CD147 mAb). The particle size and size distribution of the both nanoparticles, with antibody binding (namely CD147-CPT NPs) and without antibody (abbreviated as CPT-loaded NPs), were measured by dynamic light scattering (DLS). The morphologies of both two kinds of nanoparticles were observed by transmission electron microscope (TEM). The results of X-ray photoelectron spectroscopy (XPS) showed that CD147 mAb had been coupled to the surface of CPT-loaded NPs. Endocytosis test indicated that CD147-CPT NPs had higher uptake rate and accumulation in HepG2 cells than those of CPT-loaded NPs without antibodies, due to CD147 mAb can specifically bind to CD147 protein overexpressed in HepG2 cells. We establish a method to bond monoclonal antibodies to anti-cancer polymeric prodrugs, and endow biodegradable polymeric prodrugs with precise targeting functions to liver cancer cells.

Asunto(s)

Antineoplásicos Fitogénicos/farmacología , Basigina/química , Materiales Biocompatibles/farmacología , Camptotecina/farmacología , Carcinoma Hepatocelular/tratamiento farmacológico , Inmunoconjugados/farmacología , Neoplasias Hepáticas/tratamiento farmacológico , Antineoplásicos Fitogénicos/química , Basigina/genética , Basigina/metabolismo , Materiales Biocompatibles/química , Camptotecina/química , Carcinoma Hepatocelular/patología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Sistemas de Liberación de Medicamentos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Inmunoconjugados/química , Neoplasias Hepáticas/patología , Ensayo de Materiales , Estructura Molecular , Nanomedicina , Tamaño de la Partícula , Profármacos/química , Profármacos/farmacología

RESUMEN

Aminated poly(glycidyl methacrylate)s-based polymers for gene delivery not only can reduce toxicity and improve solubility, but can improve gene transfection efficiency and reduce protein aggregation. In this study, we first prepared poly(glycidyl methacrylate) (PGMA) via reversible addition-fragmentation chain transfer (RAFT) polymerization, and then the obtained PGMA homopolymer was post-modified with ethanol amine (EA), 1-amino-2-propanol (AP), 3-(dibutylamino)propylamine (DA) and N-(2-hydroxyethyl)ethylenediamine (HA), respectively, to yield four kinds of PGMA-based gene vectors containing hydroxyl groups (abbreviated as PGEA, PGAP, PGDA and PGHA). The effects of the different side chains and hydroxyl groups on the biological properties of these four cationic polymers were investigated. We found that the transfection efficiency of the PGHA/p53 complex was higher than those of the other three polymer/gene complexes through MTT assay and laser scanning confocal microscopy. Hence, we chose HA for further post-modification to fabricate a cationic copolymer, PCL-ss-P(PEGMA-co-GHA) (abbreviated as PGHAP), via a combination of ring opening polymerization (ROP) and RAFT copolymerization. The PCL-ss-P(PEGMA-co-GHA) amphiphilic copolymer could self-assemble into nanoparticles, which could be used to encapsulate anticancer drug doxorubicin (DOX) and compress the p53 gene to form the DOX-loaded PCL-ss-P(PEGMA-co-GHA)/p53 complex (abbreviated as DPGHAP/p53). The gel retardation assay showed that p53 gene could be well immobilized and remained stable under the electronegative conditions. MTT assay showed that the DPGHAP/p53 complex had a significant antitumor effect on A549 cells and H1299 cells compared with free DOX or/and p53 gene therapy alone. Furthermore, the test results from live cell imaging systems revealed that the DPGHAP/p53 complexes could effectively deliver DOX and the p53 gene into A549 cells. Therefore, the constructed cationic polymer PCL-ss-P(PEGMA-co-GHA) has potential application prospects as a co-vector of anticancer drugs and genes.

Asunto(s)

Antineoplásicos/administración & dosificación , Doxorrubicina/administración & dosificación , Portadores de Fármacos/química , Técnicas de Transferencia de Gen , Ácidos Polimetacrílicos/química , Proteína p53 Supresora de Tumor/genética , Células A549 , Aminación , Antineoplásicos/farmacología , Línea Celular Tumoral , Doxorrubicina/farmacología , Sistemas de Liberación de Medicamentos/métodos , Genes p53 , Terapia Genética , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Neoplasias/terapia , Transfección/métodos

RESUMEN

In this study, we report a diblock copolymer based on a polyphosphate backbone and pendant phenylboronic acid with glucose sensitivity. The copolymer, abbreviated as (PBYP-g-MPBA)-b-PEEP, was prepared via a combination of ring-opening copolymerization, "click" chemistry, and amide reaction, in which the PBYP and PEEP blocks, respectively, represent two kinds of polyphosphoester structures and MPBA represents 3-mercaptopropionic acid modified with 3-aminophenylboronic acid. The amphiphilic copolymer (PBYP-g-MPBA)-b-PEEP could self-assemble into core-shell nanoparticles (NPs) in aqueous solutions. The average particle size and morphology of the NPs were measured by dynamic light scattering and transmission electron microscopy, respectively. The phenomenon that the NPs swelled at different glucose concentrations is due to the formation of boronate esters between the diol groups of glucose and boronic acid groups of phenylboronic acid. Fluorescein isothiocyanate (FITC)-insulin was loaded into the NPs and triggered to release in the presence of glucose. The more the glucose in the release media, the more the FITC-insulin released and the faster the release rate. Methyl thiazolyl tetrazolium assays and hemolysis tests proved that the (PBYP-g-MPBA)-b-PEEP copolymers had good biocompatibility. All of these results verify that the glucose-sensitive polyphosphoester diblock copolymer is highly promising for an insulin delivery system.

Asunto(s)

Glucosa , Nanopartículas , Micelas , Tamaño de la Partícula , Polímeros

RESUMEN

Drug self-delivery systems consisting of small-molecule active drugs with nanoscale features for intracellular delivery without the need for additional polymeric carriers have drawn much attention recently. In this work, we proposed a highly efficient strategy to fabricate protonized and reduction-responsive self-assembled drug nanoparticles from an amphiphilic small-molecule camptothecin-ss-1,2,3-triazole-gemcitabine conjugate (abbreviated as CPT-ss-triazole-GEM) for combination chemotherapy, which was prepared via a Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) "click" reaction. To obtain this drug-triazole-drug conjugate, we first prepared a CPT derivate containing a propargyl group linked with a disulfide group and a GEM derivate attached to an azide group. Subsequently, the two kinds of modified drugs were connected together through a CuAAC reaction between the alkynyl and azide groups to yield the CPT-ss-triazole-GEM prodrug. The characterizations of chemical structures of these intermediates and the final product were performed by 1H NMR, Fourier transform infrared, and liquid chromatography/mass spectrometry measurements. This amphiphilic small-molecule drug-triazole-drug conjugate displayed a high drug loading content, that is, 36.0% of CPT and 27.2% of GEM. This kind of amphiphilic small-molecule prodrugs could form spherical nanoparticles in an aqueous solution in the absence of any other polymeric carriers, in which the hydrophobic CPT formed the core of the nanoparticles, whereas the hydrophilic GEM and protonated 1,2,3-triazole group yielded the shell. In the tumor microenvironment, the prodrug nanoparticles could release both pristine drugs simultaneously. Under the conditions of pH 7.4, and pH 7.4 and 2 µM glutathione (GSH), the prodrug nanoparticles could maintain stability and only 7% of CPT was leaked. However, in a high-GSH environment (pH 7.4 and 10 mM GSH) with the same incubation time, the disulfide linkage would be dissociated and lead to about 34% of CPT release. The results of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test demonstrated that these prodrug nanoparticles showed a higher cytotoxicity toward HepG2 cells than free CPT and free GEM on both 48 and 72 h of incubation. Both in vitro cellular uptake and flow cytometry results implied that these prodrug nanoparticles could be internalized by HepG2 cells with efficient drug release inside cells. The pharmacokinetics and tissue distribution of the prodrug showed a moderate half-life in vivo, and the prodrug peak concentration in most of the collected tissues appeared at 0.25 h after administration. In addition, the CPT-ss-triazole-GEM prodrug could not cross the blood-brain barrier. Even more important is the fact that there is no accumulation in tissues and a rapid elimination of this small-molecule prodrug could be achieved. In brief, this protonized and reduction-sensitive prodrug simultaneously binds both antitumor drugs and has good self-delivery behavior through the donor-acceptor interaction of the H-bonding ligand, that is, the 1,2,3-triazole group. It provides a new method for combined drug therapy.

Asunto(s)

Camptotecina/química , Química Clic/métodos , Desoxicitidina/análogos & derivados , Sistemas de Liberación de Medicamentos/métodos , Nanopartículas/química , Profármacos/química , Animales , Antineoplásicos/química , Antineoplásicos/farmacocinética , Camptotecina/análogos & derivados , Camptotecina/farmacocinética , Supervivencia Celular/efectos de los fármacos , Desoxicitidina/química , Desoxicitidina/farmacocinética , Liberación de Fármacos , Estabilidad de Medicamentos , Semivida , Células Hep G2 , Humanos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Masculino , Profármacos/farmacocinética , Ratas , Ratas Sprague-Dawley , Distribución Tisular , Triazoles/química , Triazoles/farmacocinética , Gemcitabina

RESUMEN

Giant surfactants refer to a new kind of amphiphile by incorporating functional molecular nanoparticles with polymer tails. As a size-amplified counterpart of small-molecule surfactants, they serve to bridge the gap between small-molecule surfactants and amphiphilic block copolymers. This work reports the design and synthesis of single-tailed giant surfactants carrying a hydrophobic poly(ε-caprolactone) (PCL) as the tail and a hydrophilic cage-like polyhedral oligomeric silsesquioxane (POSS) nanoparticle as the head. The modular synthetic strategy features an efficient "growing-from" and "click-modification" approach. Starting from a monohydroxyl and heptavinyl substituted POSS (VPOSS-OH), a PCL chain with controlled molecular weight and narrow polydispersity was first grown by the ring-opening polymerization (ROP) of ε-CL under the catalysis of stannous octoate, leading to a PCL chain end-capped with heptavinyl substituted POSS (VPOSS-PCL). To endow the POSS head with adjustable polarity and functionality, three kinds of hydrophilic groups, including hydroxyl groups, carboxylic acids, and amine groups, were installed to the periphery of POSS molecule by a high-efficiency thiol-ene "click" reaction. The compounds were fully characterized by NMR, gel permeation chromatography (GPC), MALDI-TOF mass spectrometry, and TGA analysis. In addition, the preliminary self-assembly study of these giant surfactants was also investigated by TEM and dynamic laser light scattering (DLS), which indicated that they can form spherical nanoparticles with different diameters in aqueous solution. This work affords a straightforward and versatile way for synthesizing single-tailed giant surfactants with diverse head surface functionalities.

RESUMEN

Amphiphilic polymeric prodrugs show improved therapeutic indices with respect to traditional hydrophobic anticancer drugs because these prodrugs can self-assemble into nanoparticles, prolong the circulation of drugs in the blood, improve the accumulation of drugs in the disease site, reduce the side effects of drugs, and achieve therapeutic effect. Here, we describe a novel pH/reduction dual-responsive polymeric prodrug, abbreviated as CPT- ss-poly(BYP- hyd-DOX- co-EEP), with simultaneous conjugating camptothecin (CPT) and doxorubicin (DOX), wherein BYP and EEP represent two cyclic phosphate monomers, respectively, that is, 2-(but-3-yn-1-yloxy)-2-oxo-1,3,2-dioxaphospholane and 2-ethoxy-2-oxo-1,3,2-dioxaphospholane. This prodrug was prepared through a polyphosphoester-DOX conjugate using a CPT derivative (CPT- ss-OH) as the initiator. CPT is linked to the terminal of polyphosphoester via disulfide carbonate, which is easy to break up under intracellular reductive environment and release the parent CPT, whereas DOX was efficiently incorporated onto the pendants of polyphosphoester through a hydrazone bond (- hyd-), which would be cleaved in the intracellular acidic medium. We show that the stable prodrug nanoparticles formed by self-assembly could release CPT and DOX simultaneously in the tumor microenvironment. The results of MTT assay demonstrate that the prodrug, which binds two antitumor drugs simultaneouly, has the properties of dual pH/reduction sensitiveness, biocompatibility, biodegradability, and effective tumor therapy.

Asunto(s)

Antineoplásicos/química , Camptotecina/química , Doxorrubicina/química , Profármacos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Camptotecina/metabolismo , Camptotecina/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Doxorrubicina/metabolismo , Doxorrubicina/farmacología , Portadores de Fármacos/química , Liberación de Fármacos , Humanos , Concentración de Iones de Hidrógeno , Interacciones Hidrofóbicas e Hidrofílicas , Microscopía Confocal , Nanopartículas/química , Polímeros/química , Profármacos/metabolismo , Profármacos/farmacología

RESUMEN

Zwitterionic polymers are a class of polymers that acts as both Lewis base and Lewis acid in solution. These polymers not only have excellent properties of hydration, anti-bacterial adhesion, charge reversal and easy chemical modification, but also have characteristics of long-term circulation and suppress nonspecific protein adsorption in vivo. Here, we describe a novel folate-targeted and acid-labile polymeric prodrug under the microenvironment of tumor cells, abbreviated as FA-P(MPC-co-PEGMA-BZ)-g-DOX, which was synthesized via a combination of reversible addition-fragmentation chain transfer (RAFT) copolymerization, Schiff-base reaction, Click chemistry, and a reaction between the amine group of doxorubicin (DOX) and aldehyde functionalities of P(MPC-co-PEGMA-BZ) pendants, wherein MPC and PEGMA-BZ represent 2-(methacryloyloxy)ethyl phosphorylcholine and polyethylene glycol methacrylate ester benzaldehyde, respectively. The polymeric prodrug could self-assemble into nanoparticles in an aqueous solution. The average particle size and morphologies of the prodrug nanoparticles were observed by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. We also investigated the in vitro drug release behavior and observed rapid prodrug nanoparticle dissociation and drug release under a mildly acidic microenvironment. The methyl thiazolyl tetrazolium (MTT) assay verified that the P(MPC-co-PEGMA-BZ) copolymer possessed good biocompatibility and the FA-P(MPC-co-PEGMA-BZ)-g-DOX prodrug nanoparticles showed higher cellular uptake than those prodrug nanoparticles without the FA moiety. The results of cytotoxicity and the intracellular uptake of non-folate/folate targeted prodrug nanoparticles further confirmed that FA-P(MPC-co-PEGMA-BZ)-g-DOX could be efficiently accumulated and rapidly internalized by HeLa cells due to the strong interaction between multivalent phosphorylcholine (PC) groups and cell membranes. This kind of multifunctional FA-P(MPC-co-PEGMA-BZ)-g-DOX prodrug nanoparticle with combined target-ability and pH responsiveness demonstrates promising potential for cancer chemotherapy.

Asunto(s)

Sistemas de Liberación de Medicamentos/métodos , Liberación de Fármacos , Ácido Fólico/metabolismo , Profármacos/química , Doxorrubicina/administración & dosificación , Ácido Fólico/farmacocinética , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Ensayo de Materiales , Metacrilatos/metabolismo , Nanopartículas/química , Neoplasias/tratamiento farmacológico , Fosforilcolina/metabolismo , Polietilenglicoles/metabolismo , Polímeros/química , Polímeros/metabolismo , Polímeros/farmacocinética , Profármacos/metabolismo , Profármacos/farmacocinética

RESUMEN

Click chemistry has increasing applications of the development of polymer materials and modification of drug carriers. The amino-yne click polymerization reacts quickly at room temperature without catalyst, and the enamine bond (-ena-) gained from the reaction is sensitive to acid and can be used to prepare stimulus-responsive polymeric prodrugs. Herein, we report an alkynyl-terminated polymer containing alternately distributed low molecular weight polyethylene glycol (PEG) and hexamethylenediamino (HMDA) linked by enamine bonds, abbreviated as A-P(PEG-alt-HMDA)-A, which was synthesized within 3 h at 35 °C without catalyst. The polymer was verified to have good water solubility, biocompatibility, and acid-sensitive fracturing. Then, a pH-responsive polymeric prodrug (DOX-ena-PPEG-ena-DOX) was further prepared through the amino-yne click reaction between the alkynyl groups of A-P(PEG-alt-HMDA)-A and the amino group of doxorubicin hydrochloride (DOX·HCl). The resulting prodrug can self-assemble into nanoparticles (NPs) in aqueous solution. The pH responsiveness of the prodrug NPs was demonstrated by a stability experiment of NPs and in vitro drug release behavior measurement. The accumulative release of doxorubicin (DOX) was tested with different pH media, which confirmed that the prodrug NPs could effectively dissociate and release drug under a weak acid microenvironment of lysosome/endosome. Subsequently, we investigated cell cytotoxicity and intracellular uptake of the prodrug. It turned out that the prodrug nanoparticles could be internalized into HeLa cells, release original DOX, and efficiently inhibit the proliferation of cancer cells. These results show that the pH-responsive DOX-ena-PPEG-ena-DOX has the potential for use in cancer therapy.

RESUMEN

Shell cross-linked (SCL) polymeric prodrug micelles have the advantages of good blood circulation stability and high drug content. Herein, we report on a new kind of pH/redox responsive dynamic covalent SCL micelle, which was fabricated by self-assembly of a multifunctional polymeric prodrug. At first, a macroinitiator PBYP- ss- iBuBr was prepared via ring-opening polymerization (ROP), wherein PBYP represents poly[2-(but-3-yn-1-yloxy)-2-oxo-1,3,2-dioxaphospholane]. Subsequently, PBYP- hyd-DOX- ss-P(DMAEMA- co-FBEMA) prodrug was synthesized by a one-pot method with a combination of atom transfer radical polymerization (ATRP) and a Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction using a doxorubicin (DOX) derivative containing an azide group to react with the alkynyl group of the side chain in the PBYP block, while DMAEMA and FBEMA are the abbriviations of N, N-(2-dimethylamino)ethyl methacrylate and 2-(4-formylbenzoyloxy)ethyl methacrylate, respectively. The chemical structures of the polymer precursors and the prodrugs have been fully characterized. The SCL prodrug micelles were obtained by self-assembly of the prodrug and adding cross-linker dithiol bis(propanoic dihydrazide) (DTP). Compared with the shell un-cross-linked prodrug micelles, the SCL prodrug micelles can enhance the stability and prevent the drug from leaking in the body during blood circulation. The average size and morphology of the SCL prodrug micelles were measured by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. The SCL micelles can be dissociated under a moderately acidic and/or reductive microenvironment, that is, endosomal/lysosomal pH medium or high GSH level in the tumorous cytosol. The results of DOX release also confirmed that the SCL prodrug micelles possessed pH/reduction responsive properties. Cytotoxicity and cellular uptake analyses further revealed that the SCL prodrug micelles could be rapidly internalized into tumor cells through endocytosis and efficiently release DOX into the HeLa and HepG2 cells, which could efficiently inhibit the cell proliferation. This study provides a fast and precise synthesis method for preparing multifunctional polymer prodrugs, which hold great potential for optimal antitumor therapy.

Asunto(s)

Antineoplásicos/administración & dosificación , Concentración de Iones de Hidrógeno , Micelas , Polímeros/química , Profármacos/química , Doxorrubicina/química , Portadores de Fármacos , Células HeLa , Células Hep G2 , Humanos , Oxidación-Reducción

RESUMEN

To improve the therapeutic efficacy and circulation stability in vivo, we synthesized a new kind of drug delivery carrier based on folic acid conjugated polyphosphoester via the combined reactions of Michael addition polymerization and esterification. The produced amphiphilic polymer, abbreviated as P(EAEP-AP)-LA-FA, could self-assemble into nanoparticles (NPs) with core-shell structure in water and reversible core cross-linked by lipoyl groups. Using the core cross-linked FA-conjugated nanoparticles (CCL-FA NPs) to encapsulate hydrophobic anticancer drug doxorubicin (DOX), we studied the stability of NPs, in vitro drug release, cellular uptake, and targeting intracellular release compared with both un-cross-linked FA-conjugated nanoparticles (UCL-FA NPs) and core cross-linked nanoparticles without FA conjugation (CCL NPs). The results showed that under the condition of pH 7.4, the DOX-loaded CCL-FA NPs could maintain stable over 72 h, and only a little DOX release (∼15%) was observed. However, under the reductive condition (pH 7.4 containing 10 mM GSH), the disulfide-cross-linked core would be broken up and resulted in 90% of DOX release at the same incubation period. The study of methyl thiazolyl tetrazolium (MTT) assay indicated that the DOX-loaded CCL-FA NPs exhibited higher cytotoxicity (IC50: 0.33 mg L-1) against HeLa cells than the DOX-loaded CCL NPs without FA. These results indicate that the core cross-linked FA-conjugated nanoparticles have unique stability and targetability.

Asunto(s)

Ácido Fólico/química , Doxorrubicina , Portadores de Fármacos , Sistemas de Liberación de Medicamentos , Células HeLa , Humanos , Nanopartículas