A Platelet Intelligent Vehicle with Navigation for Cancer Photothermal-Chemotherapy.

Controllable and visible delivery of therapeutic agents is critical for tumor precise therapy. Tumor targeting and deep penetration of therapeutic agents are still challenging issues for controllable delivery. Visible drug delivery with imaging navigation can optimize the treatment window for personalized medicine.

Peptide dendrimers as potentiators of conventional chemotherapy in the treatment of pancreatic cancer in a mouse model.

Chemotherapy is the recommended treatment for patients with advanced pancreatic ductal adenocarcinoma (PDAC). However, efficacy of traditional chemotherapy is not satisfactory due to the presence of a dense dysplastic tumor stroma which prevents drug accumulation in and deep penetration into tumors. To overcome these obstacles, we designed and synthesized peptide dendrimers as potentiators of conventional chemotherapy.

Co-administration of a branched arginine-rich polymer enhances the anti-cancer efficacy of doxorubicin.

The severe side-effects and drug resistance development of conventional chemotherapy are mainly caused by poor tumor penetration as well as nonspecific biodistribution and insufficient cellular uptake of drugs. Herein a branched arginine-rich polymer was synthesized and co-administration of this polymer with doxorubicin, a model drug of chemotherapeutic agents, overcame simultaneously the three obstacles shown above. Co-incubation of the polymer promoted doxorubicin penetration deeply into multicellular tumor spheroids and internalization into cancer cells.

One-Step Synthesis of Single-Stranded DNA-Bridged Iron Oxide Supraparticles as MRI Contrast Agents.

Despite progress on DNA-assembled nanoparticle (NP) superstructures, their complicated synthesis procedures hamper their potential biomedical applications. Here, we present an exceptionally simple strategy for the synthesis of single-stranded DNA (ssDNA) assembled FeO supraparticles (DFe-SPs) as magnetic resonance contrast agents. Unlike traditional approaches that assemble DNA-conjugated NPs via Watson-Crick hybridization, our DFe-SPs are formed with a high yield through one-step synthesis and assembly of ultrasmall FeO NPs via ssDNA-metal coordination bridges.

Polyethylenimine modified with 2,3-dimethylmaleic anhydride potentiates the antitumor efficacy of conventional chemotherapy.

Conventional chemotherapy is a standard care for many cancers at present. However, their severe dose-dependent side effects are the major impediment for successful cancer therapy. Herein nanoparticles were used as a potentiator to enhance the uptake of free chemotherapeutic agents by cancer cells during chemotherapy.

Polyion complexes of a cationic antimicrobial peptide as a potential systemically administered antibiotic.

Antimicrobial peptides (AMPs) are regarded as next-generation antibiotics to replace conventional antibiotics due to their rapid and broad-spectrum antimicrobial properties and far less sensitivity to the development of pathogen resistance. However, they are susceptible to proteolysis in vivo by endogenous or bacterial proteases as well as induce the lysis of red blood cells, which prevent their intravenous applications. In this work, polyion complex (PIC) micelles of the cationic AMP MSI-78 and the anionic copolymer methoxy poly(ethylene glycol)-b-poly(α-glutamic acid) (mPEG-b-PGlu) were prepared to develop novel antimicrobial agents for potential application in vivo.

Chlorambucil loaded in mesoporous polymeric microspheres as oral sustained release formulations with enhanced hydrolytic stability.

Chlorambucil, a chemotherapeutic agent, is usually administered orally to treat chronic lymphocytic leukemia and some other types of cancers in regimens of conventional and metronomic chemotherapies. However, the hydrolytic instability of chlorambucil is a major limitation in achieving the optimum therapeutic performance. In this work, mesoporous polymeric microspheres were prepared by free radical suspension copolymerization of methyl acrylate and divinylbenzene in the presence of porogen.

Co-administration of a charge-conversional dendrimer enhances antitumor efficacy of conventional chemotherapy.

Despite extensive investigations, the clinical translation of nanocarrier-based drug delivery systems (NDDS) for cancer therapy is hindered by inefficient delivery and poor tumor penetration. Conventional chemotherapy by administration of free small molecule anticancer drugs remains the standard of care for many cancers. Herein, other than for carrying and releasing drugs, small nanoparticles were used as a potentiator of conventional chemotherapy by co-administration with free chemotherapeutic agents.

Methotrexate-loaded porous polymeric adsorbents as oral sustained release formulations.

Methotrexate as a model drug with poor aqueous solubility was adsorbed into porous polymeric adsorbents, which was used as oral sustained release formulations. In vitro release assay in simulated gastrointestinal fluids showed that the methotrexate-loaded adsorbents showed distinct sustained release performance. The release rate increased with increase in pore size of the adsorbents.

A cross-linking strategy provides a new generation of biodegradable and biocompatible cyanoacrylate medical adhesives.

Addition polymerization usually results in polymers with long carbon-carbon main chains. Cyanoacrylate (CA) is arguably an important example of such polymerization and has gained widespread acceptance as an all-purpose adhesive. However, CA-based medical adhesives have never been approved by the U.

Polymeric micelles with α-glutamyl-terminated PEG shells show low non-specific protein adsorption and a prolonged in vivo circulation time.

Although PEG remains the gold standard for stealth functionalization in drug delivery field up to date, complete inhibition of protein corona formation on PEG-coated nanoparticles remains a challenge. To improve the stealth property of PEG, herein an α-glutamyl group was conjugated to the end of PEG and polymeric micelles with α-glutamyl-terminated PEG shells were prepared. After incubation with bovine serum albumin or in fetal calf serum, the size of the micelles changed slightly, while the size of the micelles of similar diblock copolymer but without α-glutamyl group increased markedly.

Well-defined hydrophilic molecularly imprinted polymer microspheres for efficient molecular recognition in real biological samples by facile RAFT coupling chemistry.

A facile and highly efficient new approach (namely RAFT coupling chemistry) to obtain well-defined hydrophilic molecularly imprinted polymer (MIP) microspheres with excellent specific recognition ability toward small organic analytes in the real, undiluted biological samples is described. It involves the first synthesis of "living" MIP microspheres with surface-bound vinyl and dithioester groups via RAFT precipitation polymerization (RAFTPP) and their subsequent grafting of hydrophilic polymer brushes by the simple coupling reaction of hydrophilic macro-RAFT agents (i.e.

Efficient synthesis of narrowly dispersed hydrophilic and magnetic molecularly imprinted polymer microspheres with excellent molecular recognition ability in a real biological sample.

A facile and highly efficient approach to obtain narrowly dispersed hydrophilic and magnetic molecularly imprinted polymer microspheres with molecular recognition ability in a real biological sample as good as what they show in the organic solvent-based media is described for the first time.

Morpholino-decorated long circulating polymeric micelles with the function of surface charge transition triggered by pH changes.

Micelles with surface morpholino groups were stealthy at blood and normal tissue pH (7.4) due to the unprotonated hydrophilic morpholino groups on the surfaces. At tumor pH (<7), the micelle surfaces were positively charged because of the protonation of the morpholino groups, which promoted the cellular uptake of the micelles.

Enhanced cell uptake of superparamagnetic iron oxide nanoparticles through direct chemisorption of FITC-Tat-PEG₆₀₀-b-poly(glycerol monoacrylate).

Magnetic nanoparticles (MNPs) functionalized with specific ligands are emerging as a highly integrated platform for cancer targeting, drug delivery, and magnetic resonance imaging applications. In this study, we describe a multifunctional magnetic nanoparticle system (FITC-Tat MNPs) consisting of a fluorescently labeled cell penetrating peptide (FITC-Tat peptide), a biocompatible block copolymer PEG(600)-b-poly(glycerol monoacrylate) (PEG(600)-b-PGA), and a superparamagnetic iron oxide (SPIO) nanoparticle core. The particles were prepared by direct chemisorption of PEG(600)-b-PGA conjugated with FITC-Tat peptide on the SPIO nanoparticles.

Antimicrobial and hemolytic activities of copolymers with cationic and hydrophobic groups: a comparison of block and random copolymers.

Random and diblock copolymers of 2-(N,N-dimethylamino)ethyl methacrylate and butyl methacrylate are prepared by ATRP. As mimics of cationic antimicrobial peptides, the random and diblock copolymers show similar antimicrobial activities. In contrast, the diblock copolymers have much lower hemolytic activities than the random copolymers.

Multifunctional superparamagnetic nanocarriers with folate-mediated and pH-responsive targeting properties for anticancer drug delivery.

Multifunctional nanocarriers with multilayer core-shell architecture were prepared by coating superparamagnetic Fe(3)O(4) nanoparticle cores with a mixture of the triblock copolymer methoxy poly(ethylene glycol)-b-poly(methacrylic acid-co-n-butyl methacrylate)-b-poly(glycerol monomethacrylate) and the folate-conjugated block copolymer folate-poly(ethylene glycol)-b-poly(glycerol monomethacrylate). The model anticancer agent adriamycin (ADR), containing an amine group and a hydrophobic moiety, was loaded into the nanocarrier at pH 7.4 by ionic bonding and hydrophobic interactions.

Multilayer nanoparticles with a magnetite core and a polycation inner shell as pH-responsive carriers for drug delivery.

Nanocarriers with multilayer core-shell architecture were prepared by coating a superparamagnetic Fe(3)O(4) core with a triblock copolymer. The first block of the copolymer formed the biocompatible outermost shell of the nanocarrier. The second block that contains amino groups and hydrophobic moiety formed the inner shell.

A peptide fragment derived from the T-cell antigen receptor protein alpha-chain adopts beta-sheet structure and shows potent antimicrobial activity.

A 9-residue peptide, CP-1 (GLRILLLKV-NH(2)), is synthesized by solid-phase synthesis method. CP-1 is a C-terminal amidated derivative of a hydrophobic transmembrane segment (CP) of the T-cell antigen receptor (TCR) alpha-chain. CP-1 shows broad-spectrum antimicrobial activities against Gram-positive and Gram-negative bacteria with the minimal inhibitory concentration (MIC) values between 3 and 77microM.

Modification of antimicrobial peptide with low molar mass poly(ethylene glycol).

PEGylation of peptide drugs prolongs their circulating lifetimes in plasma. However, PEGylation can produce a decrease in the in vitro bioactivity. Longer poly(ethylene glycol) (PEG) chains are favourable for circulating lifetimes but unfavourable for in vitro bioactivities.

Immobilization of penicillin G acylase on poly[(glycidyl methacrylate)-co-(glycerol monomethacrylate)]-grafted magnetic microspheres.

Poly[(glycidyl methacrylate)-co-(glycerol monomethacrylate)]-grafted magnetic microspheres were prepared by graft random copolymerization via ATRP from polymer microspheres with dispersed Fe(3)O(4) nanoparticles. Penicillin G acylase (PGA) was immobilized onto the polymer brush-grafted magnetic microspheres. The immobilized PGA prepared with initial glycidyl methacrylate/glycerol monomethacrylate ratios of 40/60 to 60/40 possessed higher catalytic activity than that prepared with higher proportions of glycidyl methacrylate in the initial monomer mixture.

Biocompatible superparamagnetic iron oxide nanoparticle dispersions stabilized with poly(ethylene glycol)-oligo(aspartic acid) hybrids.

Methoxypoly(ethylene glycol)-oligo(aspartic acid) (MPEG-Asp(n)-NH(2), n = 2-5) hybrid block copolymers were synthesized and used as stabilizers to prepare superparamagnetic Fe(3)O(4) nanoparticles with magnetite as the inner core and and poly(ethylene glycol) as the hydrophilic outer shell. The aqueous dispersions of the nanoparticles were stable at pH 2-11 and in 1M NaCl solution, when repeat number, n, was 3 or more. Transmission electron microscopy showed that the nanoparticles, stabilized with MPEG-Asp(3)-NH(2), were about 14 nm in diameter.

The synergistic effect between hydrophobic and electrostatic interactions in the uptake of amino acids by strongly acidic cation-exchange resins.

The goal of this work was to investigate the synergistic effect between the electrostatic and hydrophobic interactions upon the uptake of organic ions with hydrophobic moieties by ion-exchange resins with hydrophobic matrixes. The uptake of neutral amino acids by a macroporous polystyrene-based strongly acidic cation-exchange resin (D001) and two strongly acidic cation-exchange resins (poly(2-acrylamido-2-methyl propanesulfonic acid) and poly(vinylsulfonic acid)) with much less hydrophobic matrixes essentially follow an ion exchange stoichiometry. However, the thermodynamic parameters of the uptakes indicate that besides electrostatic interaction, hydrophobic interaction also contributes to the affinity of the amino acids with hydrophobic side chains for D001.

Deletion of two C-terminal Gln residues of 12-26-residue fragment of melittin improves its antimicrobial activity.

In our previous paper it was shown that the two C-terminal Gln residues of a C-terminal 15-residue fragment, Mel(12-26) (GLPALISWIKRKRQQ-NH2), of melittin and a series of individual substituted analogues might not involved in the interaction with bacterial membranes. In this paper, peptides with one and two Gln residues deletion, respectively, Mel(12-25) and Mel(12-24), were synthesized and characterized. Both of the deletion peptides showed higher antimicrobial activities than the parent peptide, Mel(12-26).