Reduction-responsive diblock copolymer-modified gold nanorods for enhanced cellular uptake

Reduction-responsive polymer micelles are highly promising drug carriers with better tumor therapeutic effect, which can be achieved by controlled drug release under stimulation. Gold nanorods (AuNRs) have attracted considerable attention due to their unique optical and electronic properties when used for biomedical applications. Herein, the lipoic-acid-functionalized reduction-responsive amphiphilic copolymer poly(ε-caprolactone)-b-poly[(oligoethylene glycol) acrylate] (LA–PCL–SS–POEGA) with a disulfide group between the two blocks was prepared to modify AuNRs via Au–S bonds. The size and morphology of AuNRs@LA–PCL–SS–POEGA were measured by dynamic laser light scattering (DLS) and transmission electron microscopy (TEM) methods. The stabilities of AuNRs@LA–PCL–SS–POEGA in different types of media were studied by UV/vis spectroscopy and DLS techniques. The results show that AuNRs@LA–PCL–SS–POEGA gradually aggregate in a concentrated salt solution containing 150 mM dithiothreitol (DTT), but exhibit high stability in a non-reducing environment. Near infrared (NIR)-induced heating of AuNRs@LA–PCL–SS–POEGA was investigated in an aqueous solution under NIR laser irradiation (808 nm), revealing that AuNRs@LA–PCL–R–POEGA maintain excellent photothermal conversion efficiency after modification. When compared with non-reduction responsive AuNRs@LA–PCL–CC–POEGA, the in vitro internalization of AuNRs@LA–PCL–SS–POEGA demonstrates that the reduction-responsive polymer could enhance the cellular uptake of nanoparticles measured by inductively coupled plasma mass spectrometry (ICP-MS) and TEM.

Gold nanorod (AuNRs) modified by reduction-responsive amphiphilic copolymer poly(ε-caprolactone)-b-poly[(oligoethylene glycol)acrylate] (LA–PCL–SS–POEGA) can enhance the cellular uptake of AuNRs, presumably due to the aggregation under reducing environment in the cells.     

Novel amphiphilic graft block azobenzene-containing copolymer with polypeptide block: synthesis,self-assembly and photo-responsive behavior

Well-defined amphiphilic graft block azobenzene-containing copolymer with polypeptide block was synthesized via a combination of copper-mediated atom transfer radical polymerization (ATRP), ring-opening polymerization and click reaction. The alkyne-terminated poly[6-(4-methoxy-azobenzene-4′-oxy)hexyl methacrylate] (PAzoMA) was synthesized by ATRP with a bromine-containing alkyne bifunctional initiator, and the azido-terminated poly(γ-2-chloroethyl-l-glutamate) (PCELG) was synthesized by ROP of γ-2-chloroethyl-l-glutamate-N-carboxyanhydride (CELG-NCA), then the two homopolymers were conjugated by click reaction to afford block azobenzene-containing copolymer PAzoMA-b-PCELG. The chloro groups in PCELG block were transformed into azido groups via azide reactions, and the alkyne-terminated MPEG was grafted to the polypeptide block to afford the final product PAzoMA-b-poly((l-glutamate)-graft-methoxy poly(ethylene glycol)) (PAzoMA-b-(PELG-g-MPEG)) by click reaction. Giant vesicles (micrometer size) were obtained from the amphiphilic graft block copolymer PAzoMA-b-(PELG-g-MPEG) through a solution self-assembly due to the rigid PAzoMA chains and polypeptide chains with the α-helical structure. The investigation of the photo-isomerization behavior of PAzoMA-b-(PELG-g-MPEG) in solution and in vesicular solution showed trans–cis isomerization in solution was quicker than that in vesicular solution and azobenzene J-aggregates in the vesicle solution were only observed. The formation mechanisms of the vesicles were also explored. The research results may provide guidelines for the study of complex copolymers containing different types of rigid chains.

Giant vesicles (micrometer size) were prepared from novel amphiphilic graft block azobenzene-containing copolymer with polypeptide block synthesized via a combination of ATRP, ROP and click reaction.     

Mussel-inspired nano-silver loaded layered double hydroxides embedded into a biodegradable polymer matrix for enhanced mechanical and gas barrier properties

In this paper, a facile, green and mussel-inspired method is presented to prepare silver loaded layered double hydroxides (Ag-LDHs@PDA and Ag-LDHs@TA–Fe(iii)) using a pre-synthesis polydopamine (PDA)/tannic acid (TA)–Fe(iii) layer as a nanoscale guide and PDA/TA itself as a reducing reagent to form uniform silver nanoparticles (AgNPs) on the surface of modified LDHs. Meanwhile, another kind of LDH, Ag-LDHs(PVP), was prepared via the direct reduction of the precursor [Ag(NH₃)₂]⁺ with polyvinyl pyrrolidone (PVP). And three kinds of Ag-LDHs/poly(ε-caprolactone) (PCL) nanocomposite were prepared by blending Ag-LDHs and pure PCL via a solution casting method to obtain homogeneous films. It is shown that the obtained AgNPs are distributed on the LDH surfaces uniformly. And the high loading and medium size of the AgNPs present in Ag-LDHs(PVP) give it the best antibacterial properties. However, compared with Ag-LDHs(PVP), the better dispersibilities of Ag-LDHs@PDA and Ag-LDHs@TA–Fe(iii) contribute to the greater aspect ratios of Ag-LDHs in the matrices, resulting in an increase in the number of tortuous paths for gas diffusion. Meanwhile, Ag-LDHs@PDA and Ag-LDHs@TA–Fe(iii) have stronger interactions with the PCL matrix, which is favorable for the existence of less interface defects in the matrix, resulting in an improvement in the mechanical and gas barrier properties. Therefore, mussel-inspired antibacterial Ag-LDHs/PCL nanocomposites show preferable mechanical and gas barrier properties.

A facile, green and mussel-inspired method is presented to prepare Ag loaded LDHs using a pre-synthesis PDA/TA–Fe(iii) layer as a nanoscale guide and PDA/TA itself as a reducing reagent to form uniform AgNPs on the surface of modified LDHs.     

The guest polymer effect on the dissolution of drug–polymer crystalline inclusion complexes

A drug–polymer crystalline inclusion complex (IC) is a novel solid form of drug, in which drug molecules form parallel channels, and linear polymer chains reside in these channels. In this study, we used carbamazepine (CBZ) as a model drug, and directly studied the effect of different types of guest polymers on the dissolution properties of drug–polymer ICs. We successfully prepared ICs formed from CBZ with hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(ε-caprolactone) (PCL), respectively, and confirmed that these two drug–polymer ICs both had the same channel-type crystal structure as CBZ form II. During the dissolution test, CBZ–PEG IC showed a faster dissolution rate compared to CBZ form II under both sink and non-sink conditions. CBZ–PCL IC was confirmed to be more stable in aqueous medium, as the guest polymer PCL delayed its transformation to less-soluble crystals during dissolution.

Guest polymers have significant influence on the dissolution of drug–polymer inclusion complex crystals.     

Synergistic effect of Pd content and polyelectrolyte multilayer structure on nitrobenzene hydrogenation in a microreactor

In this study, we proposed a Pd–polyelectrolyte multilayer (PEM) hybrid film grafted on the polydopamine coated interior wall of a microreactor for nitrobenzene hydrogenation. Here, Pd nanoparticles were in situ synthesized in the PEMs consisting of poly(diallyldimethylammonium chloride) and poly(styrene sulfonate) via a two-stage ion-exchange and reduction process. The preparation process was monitored by UV-vis spectroscopy, which confirmed the formation of Pd in the PEM film. In addition, SEM and ICP-OES results indicated that the Pd content in the PEM film could be controlled by the number of the ion exchange and reduction cycles. Experimental results also showed that the prepared Pd–PEM hybrid film was active for the hydrogenation of nitrobenzene. The microreactor with the Pd–PEM hybrid film via multiple times had the increased catalyst loading, leading to a high yield of aniline and much better durability. In addition, it was also found that the NaCl concentration in the polyelectrolyte solution could affect the structure of the PEM film and therefore the Pd loading and catalytic performance.

In this study, we developed a Pd–PEMs hybrid film grafted on the polydopamine coated interior wall of a microreactor for nitrobenzene hydrogenation.     

Facile UV-induced covalent modification and crosslinking of styrene–isoprene–styrene copolymer via Paterno–Büchi [2 + 2] photocycloaddition

The chemical functionalization or modification of polymers to alter or improve the physical and mechanical properties constitutes an important field in macromolecular research. Fabrication of polymeric materials via structural tailoring of commercial or commodity polymers that are produced in vast quantities especially possess unique advantages in material applications. In the present study, we report on benign chemical modification of unsaturated styrene–isoprene–styrene (SIS) copolymer using available backbone alkene groups. Covalent attachment of aldehyde functional substrates onto reactive isoprene double bond residues was conveniently carried out using UV-induced Paterno–Büchi [2 + 2] cycloaddition. Model organic compounds with different structures were utilized in high efficiency chemical modification of parent polymer chains via oxetane ring formation. Functionalization studies were confirmed via¹H NMR, FT-IR and SEC analyses. The methodology was extended to covalent crosslinking of polymer chains to obtain organogels with tailorable crosslinking degrees and physical characteristics. Considering the outstanding elastic properties of unsaturated rubbers and their high commercial availability, abundant reactive double bonds in backbone chains of these polymers offer easy to implement structural modification via proposed Paterno–Büchi photocycloaddition.

Paterno–Büchi reaction is reported as a convenient chemical reaction tool to modify unsaturated copolymer elastomers.     

Binary catalytic system for homo- and block copolymerization of ε-caprolactone with δ-valerolactone

The combined interaction of 2,3,6,7-tetrahydro-5H-thiazolo[3,2-a] pyrimidine (ITU) as the organocatalytic nucleophile with YCl₃ as Lewis acid cocatalyst, generating ITU/YCl₃, was employed for homo- and copolymerization of ε-caprolactone (CL) with δ-valerolactone (VL). Poly(caprolactone) (PCL) and poly(caprolactone)–poly(ethylene glycol)–poly(caprolactone) (PCL–PEG–PCL) triblock copolymer and poly(valerolactone)–poly(caprolactone)–poly(ethylene glycol)–poly(caprolactone)–poly(valerolactone) (PVL–PCL–PEG–PCL–PVL) pentablock copolymer were successfully prepared by ring-opening polymerization (ROP) of CL employing ITU/YCl₃ as catalyst in the presence of benzyl alcohol (BnOH) or poly(ethylene glycol) (PEG) as initiator, respectively. The reaction was systematically optimized, and the architecture, molecular weight and thermal properties of the polymers were characterized by NMR, FTIR, SEC and DSC analyses. Finally, a plausible polymerization mechanism was proposed.

The combined interaction of 2,3,6,7-tetrahydro-5H-thiazolo[3,2-a] pyrimidine (ITU) as the organocatalytic nucleophile with YCl₃ as Lewis acid cocatalyst, generating ITU/YCl₃, was employed for homo- and copolymerization of CL with VL.     

Novel azobenzene-based amphiphilic copolymers: synthesis,self-assembly behavior and multiple-stimuli-responsive properties

A series of novel azobenzene-based amphiphilic random copolymers P(POSSMA-co-AZOMA-co-DMAEMA) were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. A light and reduction dual-responsive azo group, pH-responsive tertiary amine group and super hydrophobic POSS moiety were incorporated into the polymer chain to generate multi-stimuli-responsiveness. Self-assembly of these amphiphilic copolymers led to the formation of spherical micelles in aqueous solution. The light, pH and reduction responsive properties of the micelles were investigated systematically by DLS, TEM, UV-vis, FTIR and NMR. The azo groups can undergo trans–cis isomerization under UV light irradiation, thus causing a diameter change of the micelles. Owing to the large proportion of tertiary amine groups in amphiphiles, these micelles showed sensitive pH-response behavior. The hydrophobic azo pendant in the polymer chain completely reduced to a more hydrophilic substituted aniline in a reductive environment, resulting in the increase of overall hydrophilicity of amphiphiles and the disassembly of polymeric micelles. Owing to these multi-stimuli–responses, the polymeric micelles showed rapid and efficient release properties of hydrophobic molecules in response to pH and reductive stimuli.

Polymeric micelles encapsulating and releasing hydrophobic guest molecules.     

Mitochondria-targeted curcumin loaded CTPP–PEG–PCL self-assembled micelles for improving liver fibrosis therapy

Liver fibrosis, originating from activated hepatic stellate cells (HSCs), is receiving much attention in the treatment of clinical liver disease. In this study, mitochondria-targeted curcumin (Cur) loaded 3-carboxypropyl-triphenylphosphonium bromide–poly(ethylene glycol)–poly(ε-caprolactone) (CTPP–PEG–PCL) micelles were constructed to prolong the systemic circulation of Cur, improve the bioavailability of Cur and play a precise role in anti-fibrosis. The prepared Cur–CTPP–PEG–PCL micelles with a spherical shape had satisfactory dispersion, low critical micelle concentration (CMC) and high encapsulation efficiency (92.88%). The CTPP modification endowed good endosomal escape ability to the CTPP–PEG–PCL micelles, and micelles could be selectively accumulated in mitochondria, thereby inducing the enhanced cell proliferation inhibition of HSC-T6 cells. Mitochondrial Membrane Potential (MMP) was greatly reduced due to the mitochondrial-targeting of Cur. Moreover, the system circulation of Cur was extended and bioavailability was significantly enhanced in vivo. As expected, Cur loaded CTPP–PEG–PCL micelles were more effective in improving liver fibrosis compared with Cur and Cur–mPEG–PCL micelles. In conclusion, the Cur–CTPP–PEG–PCL based micelles can be a potential candidate for liver fibrosis treatment in future clinical applications.

A mitochondria-targeting micelle system based on CTPP–PEG–PCL polymer was designed to deliver curcumin to active HSC-T6 cells and prolong the systemic circulation and bioavailability of curcumin in vivo for effective treatment of liver fibrosis.     

A versatile strategy for the synthesis and mechanical property manipulation of networked biodegradable polymeric materials composed of well-defined alternating hard and soft domains

The present paper proposes a versatile strategy for the synthesis and mechanical property manipulation of networked biodegradable polymeric materials composed of well-defined alternating soft and hard domains. As an example of the strategy, we selected biodegradable poly(l-lactide) (PLLA) and poly(ε-caprolactone) (PCL) as the hard and soft components, respectively, and synthesized networked biodegradable polymeric materials composed of well-defined alternating PLLA and PCL domains with different l-lactide (LLA) unit contents via crosslinking of well-defined four-armed diblock copolymers of PLLA and PCL (4-C-L). The strategy reported here, which is also applicable to non-biodegradable polymeric materials, successfully facilitated the synthesis of the networked biodegradable materials composed of alternating hard and soft domains and their mechanical properties of the synthesized materials were largely manipulated by the LLA unit contents of the precursor four-armed diblock 4-C-L copolymers. Moreover, the crystallization behavior and thermal properties of 4-C-L copolymers before and after crosslinking were investigated and discussed.

Networked materials composed of well-defined alternating domains of two types of biodegradable polymers, hard poly(l-lactide) and soft poly(ε-caprolactone), were successfully synthesized.     

Preparation and characterization of POSS-containing poly(perfluoropolyether)methacrylate hybrid copolymer and its superhydrophobic coating performance

To design a mechanically stable and superhydrophobic coating, a polyhedral oligomeric silsesquioxane (POSS)-containing poly(perfluoropolyether)methacrylate (PFPEM) hybrid copolymer (PFPEM–POSS) was synthesized via a free-radical solution polymerization with PFPEM, 1H,1H,2H,2H-perfluorooctyl acrylate, methyl (meth)acrylate, n-butyl acrylate, hydroxypropyl acrylate, methacryloxy propyl trimethoxy silane, and methacrylisobutyl POSS; and azobisisobutyronitrile as an initiator. Hydrophobic coatings were formed on substrates by a facile one-step dip-coating method in a solution mixture of diethylene glycol dimethyl ether with the PFPEM–POSS hybrid copolymer. The chemical structure of the PFPEM–POSS copolymer and the surface morphology and performance of the PFPEM–POSS coatings were investigated. The results indicate that, under POSS aggregation via the fluorophilic/oleophilic co-monomer phase separation and owing to the low-surface-energy poly(perfluoropolyether)methacrylate incorporated into the copolymer, PFPEM–POSS exhibited a hierarchical micro-nano roughness in atomic force microscopy observations and provided the treated substrates with excellent hydrophobicity and abrasion resistance. As a result, the water contact angle reached 152.3° on the treated glass.

A coating with excellent superhydrophobicity and durability was built via incorporating an environmentally-friendly poly(perfluoropolyether)methacrylate copolymer into polyhedral oligomeric silsesquioxane (POSS).     

An NIR-triggered drug release and highly efficient photodynamic therapy from PCL/PNIPAm/porphyrin modified graphene oxide nanoparticles with the Janus morphology

This project aimed to investigate the synthesis and characteristics of stimuli-responsive nanoparticles with different morphologies. In the first step, graphene oxide was synthesized based on the improved Hummers'' method. Then, thermo-responsive poly(N-isopropylacrylamide-co-N-(hydroxymethyl)acrylamide), an amphiphilic copolymer, and poly(caprolactone) (PCL), a hydrophobic polymer, were used to prepare Janus and mixed graphene oxide-based nanoparticles. Fluorescence microscopy was utilized to confirm the Janus structure by labeling the mixed and Janus NPs with fluorescent hydrophobic and hydrophilic dyes via a solvent-evaporation method. Then, terminally modified carboxyl porphyrin (TPPC3-COOH), used as the second generation photosensitizer, was grafted to the copolymer surrounding the mixed and Janus NPs. Next, quercetin, a hydrophobic anti-cancer drug, was loaded onto both NPs to accomplish NIR-triggered photodynamic- and chemo-therapy. Finally, the drug loading, encapsulation efficiency, and in vitro release of thermo-responsive NPs were investigated at temperatures of 37 °C and 40 °C as well as under laser irradiation (808 nm).

This project aimed to investigate the synthesis and characteristics of stimuli-responsive nanoparticles with different morphologies.     

Synthesis of crosslinkable diblock terpolymers PDPA-b-P(NMS-co-OEG) and preparation of shell-crosslinked pH/redox-dual responsive micelles as smart nanomaterials

Crosslinked polymer nanomaterials have attracted great attention due to their stability and highly controllable drug delivery; herein, a series of well-defined amphiphilic PDPA-b-P(NMS-co-OEG) diblock terpolymers (P1–P3) were designed and prepared via RAFT polymerization and were self-assembled into non-cross-linked (NCL) nanomicelles, which were further prepared into shell-cross-linked (SCL) micelles via cystamine-based in situ shell cross-linking. Using P3 as an optimized polymer, SCL-P3 micelles were prepared, which demonstrated remarkable pH/redox-dual responsive behaviour. For drug delivery, camptothecin (CPT)-loaded SCL-P3 micelles were prepared and showed much higher CPT-loading capability than their NCL-P3 counterparts. Notably, the SCL-P3 micelles showed good synergistic pH/redox-dual responsive CPT release properties, making them potential “smart” nanocarriers for drug delivery.

A series of well-defined amphiphilic PDPA-b-P(NMS-co-OEG) diblock terpolymers were prepared via RAFT polymerization and self-assembled into non-cross-linked nanomicelles, and then shell-cross-linked micelles via cystamine-based in situ shell cross-linking.     

Switchable conformational changes of DNA nanogel shells containing disulfide–DNA hybrids for controlled drug release and efficient anticancer action

Oligonucleotide strands containing dithiol (–SS–) groups were used as the co-crosslinkers in PNIPA–AAc based nanogels (NGs). They hybridized with PEG–oligonucleotides introduced into the gels. The specific DNA hybrid formed in the nanogel/nanocarrier was involved in highly efficient accumulation of intercalators. The presence of –SS– groups/bridges improved the storing efficiency of doxorubicin (Dox) in DNA hybrids by 53, 40 and 20% compared to regular, single stranded and regular double stranded DNA crosslinkers, respectively. The explicit arrangement of the hybrids in the carrier enabled their reduction by glutathione and an effective cancer treatment while the side toxicity could be reduced. Compared to the NGs with traditional crosslinkers and those containing typical dsDNA-based hybrids, an improved, switchable and controlled drug release occurred in the novel NGs. Since the novel NGs can release the oligonucleotide strands during their degradation, this gives an opportunity for a combined drug-gene therapy.

Switchable conformational changes of multiresponsive nanogels containing disulfide/DNA hybrid shells for pulsative drug release.     

Effect of stereocomplex crystal and flexible segments on the crystallization and tensile behavior of poly(l-lactide)

The effects of poly(ethylene glycol) (PEG) and/or poly(d-lactide) (PDLA) blocks on the crystallization and mechanical properties of poly(l-lactide) (PLLA) were investigated systematically via differential scanning calorimetry (DSC), polarized optical microscopy (POM), wide-angle X-ray diffraction (WAXD) and tensile testing. The structural evolution during uniaxial stretching of the obtained blends above the glass transition temperature was studied by in situ WAXD. It was observed that the stereocomplex (SC) crystals promoted the nucleation of PLLA homocrystals (α/α′ crystal), and flexible PEG blocks could enhance the spherulitic growth rate. The PLLA/PDLA–PEG–PDLA had a higher elongation at break than that of PLLA/PDLA without significant loss in tensile strength and stiffness. In situ WAXD showed that the PLLA/PDLA–PEG–PDLA crystallized faster during stretching. It was shown that the incorporation of SC crystals and flexible PEG blocks could not only accelerate the crystallization but also improve the toughness of PLLA.

Effect of stereocomplex crystal and PEG segments in blends on the crystallization and tensile behavior of PLLA.     

Preparation and properties of a novel poly(lactic-acid)-based thermoplastic vulcanizate from both experiments and simulations

A novel bio-based thermoplastic vulcanizate (TPV) material consisting of poly(lactic acid) (PLA) and a novel polymeric slide ring material (SeRM) was fabricated via isocyanate-induced dynamic vulcanization. The microscopic morphology, thermal properties, biocompatibility, and mechanical properties of the SeRM/PLA TPV material were comprehensively investigated, in turn by transmission electron microscopy, differential scanning calorimetry, in vitro cytotoxicity test, electron tension machine, and molecular dynamics simulations. Phase inversion in TPV was observed during the dynamic vulcanization, and TEM images showed that SeRM particles that were dispersed in PLA continuous phase had an average diameter of 1–4 μm. Results also indicated that an optimum phase inversion morphology was obtained at the SeRM/PLA blending ratio of 70/30 w/w. Glass transition temperature of PLA was found to be slightly decreased, owing to the improvement in interface compatibility by chemically bonding the PCL side chains (of SeRM molecules) and PLA chains. The tensile strength and elongation at break of TPVs were approximately 14.7 MPa and 164%, respectively, at SeRM/PLA blending ratio of 70/30, owing to the unique sliding effect of SeRM molecules when subjected to deformations. Cytotoxicity test results proved that the bio-based TPVs were fully non-toxic to L929 cells. In such aspects we believe that the bio-based TPV can be a promising material in the biomedical applications as an alternative of traditional commodity plastics.

A novel bio-based thermoplastic vulcanizate (TPV) material consisting of poly(lactic acid) (PLA) and a novel polymeric slide ring material (SeRM) was fabricated via isocyanate-induced dynamic vulcanization.     

A novel carboxylic-functional indole-based aerogel for highly effective removal of heavy metals from aqueous solution via synergistic effects of face–point and point–point interactions

A new type of carboxylic-functional indole-based aerogel (CHIFA) has been successfully prepared via a facile sol–gel technology, which possessed a highly effective removal of heavy metals from aqueous solution through the synergistic effects of face–point and point–point interactions.

A new type of carboxylic-functional indole-based aerogel (CHIFA) has been successfully prepared, which possessed highly effective removal of heavy metals from aqueous solution through the synergistic effects of face–point and point–point interactions.     

Hybrid hydrogels derived from renewable resources as a smart stimuli responsive soft material for drug delivery applications

The design and synthesis of amphiphilic molecules play a crucial role in fabricating smart functional materials via self-assembly. Especially, biologically significant natural molecules and their structural analogues have inspired chemists and made a major contribution to the development of advanced smart materials. In this report, a series of amphiphilic N-acyl amides were synthesized from natural precursors using a simple synthetic protocol. Interestingly, the self-assembly of amphiphiles 6a and 7a furnished a hydrogel and oleogel in vegetable oils. Morphological analysis of gels revealed the existence of a 3-dimensional fibrous network. Thermoresponsive and thixotropic behavior of these gels were evaluated using rheological analysis. A composite gel prepared by the encapsulation of curcumin in the hydrogel formed from 7a displayed a gel–sol transition in response to pH and could act as a dual channel responsive drug carrier.

The design and synthesis of amphiphilic molecules play a crucial role in fabricating smart functional materials via self-assembly.     

Azide–alkyne cycloaddition reactions in water via recyclable heterogeneous Cu catalysts: reverse phase silica gel and thermoresponsive hydrogels

Functionalized reverse phase silica gel and thermoresponsive hydrogels were synthesized as heterogeneous catalysts supports. Cu(i) and Cu(ii) catalysts immobilized onto two types of supports were prepared and characterized. The copper catalyzed azide–alkyne cycloaddition was performed in water via a one-pot reaction and yielded good results. These catalysts are air stable and reusable over multiple uses.

Azide–alkyne cycloaddition reactions were performed via copper catalysts immobilized onto two types of supports in water.     

Polymeric nano-vesicles via intermolecular action to load and orally deliver insulin with enhanced hypoglycemic effect

To date few polymeric vesicles have been investigated to improve oral insulin (INS) absorption due to their limited loading capacity. Therefore, an amphiphilic polyphosphazene (PEOP) containing lipid-like octadecylphosphoethanolamine (OPA) groups and amino-modified poly(ethylene glycol) at the proper ratio was designed and synthesized in this study. It was found that PEOP can self-assemble into nano-vesicles, which displayed considerable loading capability for INS by taking advantage of the synergetic effect of the interaction between OPA and INS and the physical encapsulation by the aqueous lumen of the vesicles. Furthermore, PEOP vesicles can promote INS absorption across the subsequent lymphatic transport of PEOP vesicles after their uptake by the enterocytes in the gastrointestinal tract, and consequently achieve better hypoglycemic effects in vivo. These results suggested that PEOP vesicles have great potential as oral INS carriers for diabetes therapy.

Insulin (INS) was loaded into PEOP nano-vesicles via intermolecular actions and delivered orally through lymphatic transport with promising hypoglycemic effect.