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Fluorescent and glucose-sensitive hyperbranched poly(amidoamine)s (HPAMAMs-B) were synthesized via Michael addition of 1-(2-aminoethyl) piperazine, methyl acrylate, and 3-aminobenzeneboronic acid (APBA). These hyperbranched polymers emitted chartreuse photoluminescence and showed emission band at 378 nm under excitation wavelength. The intensity of emission band was enhanced with increasing the amount of APBA in HPAMAMs-B. The glucose sensitivity of HPAMAMs-B has been investigated at different glucose concentrations and pH conditions. These hyperbranched polymers showed potential for biomedical applications such as fluorescence imaging technology and glucose detecting sensors.

The grafting of graphene oxide (GO) with a cyclic ether monomer, e-caprolactone (e-CL), directly affords graphene-PCL nanocomposites. The resulting nanocomposites show good solubility in the solvents of polymers, exfoliation of graphene in the polymer matrix and excellent mechanical properties and robustness under bending.

For improving dispersion of carbon nanotubes (CNTs) in a polymer matrix, multiwalled carbon nanotubes (MWCNTs) were first modified by ring-opening polymerization of the terminal hydroxyl of MWCNTs with e-caprolactone (e-CL). Then, the modified MWCNTs were added into polyurethane (PU) and MWCNTs/PU For improving dispersion of carbon nanotubes (CNTs) in a polymer matrix, multiwalled carbon nanotubes (MWCNTs) were first modified by ring-opening polymerization of the terminal hydroxyl of MWCNTs with e-caprolactone (e-CL). Then, the modified MWCNTs were added into polyurethane (PU) and MWCNTs/PU composite fibers were prepared by electrospinning and collected in the form of membranes. The morphology and microstructure of the composite nanofibers were analyzed by SEM. The relationship between the tensile properties of the membranes and the mass fraction of the MWNTs was revealed by tensile testing.

Hyperbranched poly(3-ethyl-3-(hydroxymethyl)oxetane) (HPBO), modified by S-1-dodecyl-S′-(α, α-dimethyl-α′′-acetic acid) trithiocarbonate (DMP) to form a RAFT macroinitiator, and then two monomers, 2-(dimethylamino)ethyl-methacrylate (DMAEMA) and acrylic acid (AA), were polymerized to obtain novel pH- and thermo-sensitive polymers with a hyperbranched polymer core. These polymers exhibited phase transitions in response to pH and temperature. They were possible to harvest a bioactive molecule, indometacin, from solution using the phase transition of these pH- and thermo-sensitive polymers. Various parameters, such as percent loading of drugs, pH, temperature and nature of the release media on the release profiles, were investigated. The resultant polymer carriers can potentially be used for the controlled release of the anti-inflammatory drug indometacin.

Due to their unique characteristics, dendrimers have attracted a great deal of attention over the past few years. The reason why they are of eminent interest in drug-delivery applications is that they have uniform size, water solubility, modifiable surface functionality and available internal cavities. Moreover, the high level of control over the dendritic architecture distinguishes them as ideal carriers. The bioactive agents may be encapsulated into the interior void spaces of the dendrimers or conjugated onto the dendrimer surface. Thus, they contribute to overcoming the challenge that quite a few drugs have low water solubility or cell membrane permeability and, therefore, never benefit patients. In this paper, we give a brief introduction of the synthesis of dendrimers, including divergent approach and convergent approach, and review two strategies used for drug-delivery applications and a vastly important function for gene transfection.

A multiarm star polymer, poly(3-ethyl-3-oxetanemethanol)-graft-poly(2-dimethyl aminoethyl methacrylate) (PEOM-g-PDMAEMA), with a three-dimensional structure was synthesized via cationic ring-opening polymerization and atom transfer radical polymerization (ATRP). The polymer, consisting of a hydrophobic hyperbranched polyether (PEOM) inner core and hydrophilic poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) multiarm shell, was used as the host for molecular encapsulations, and water-soluble dye (Congo Red) was selected as the corresponding guest molecule. Due to the multiarm structure and inner polar core, the synthesized polymer could be used as carrier for encapsulation and release of the guest molecule. The skeleton of this polymer played an important role in the procedure of guest encapsulation. The influences of controlled pH on encapsulation performance and release behaviors were mainly investigated and examined in vitro in simulated synthetic body fluids. This polymer system could be an attractive...

A multiarm star amphiphilic polymer with a three-dimensional structure was synthesized via melt polycondensation and atom transfer radical polymerization (ATRP). The polymer, consisting of a hydrophobic hyperbranched polyester (HPE) inner core and hydrophilic poly(2-dimethylaminoethyl methacrylate) (PDMAEMA) multiarm shell, was used as the host for molecular encapsulation, and water-soluble dye (Congo Red) was selected as the corresponding guest molecule. Due to the hyperbranched structure and inner polar core, the synthesized polymer was used as load carrier for encapsulation and release of Congo Red. The skeleton of these polymers played an important role in the procedure of guest-encapsulation. The influences of controlled pH on encapsulation and release behaviors were investigated and examined in vitro in simulated synthetic body fluid. This co-polymer system should be an attractive candidate for drug delivery in aqueous media and could provide the phase-transfer carriers between water and organic media.

A hyperbranched polymer (HBPO–PCL) consisting of a hyperbranched polyether (HBPO) inner core and biodegradable poly(e-caprolactone) (PCL) shell was synthesized and used as the host for molecular encapsulation. A water-soluble dye (acid orange 7, AO 7) was selected as the corresponding guest molecule. Due to the hyperbranched structures and inner polar core, the hyperbranched polymer can be used as phase-transfer agent for reversible encapsulation and release of AO 7. The skeleton of these polymers played an important role in the procedure of guest-encapsulation. The effect of pH on phase-transfer performance and release behaviors were mainly investigated and examined in a in vitro simulated synthetic body fluids. Thus, this co-polymer system should be an attractive candidate for drug-delivery systems in aqueous media and could provide the phase-transfer carriers between water and organic media.

The present review deals with the design and preparation of environment-sensitive hyperbranched polymers, such as pH-, temperature-sensitive and salt-triggered polymers, in order to be employed as drug-delivery system. In particular, using known and well-characterized basic hyperbranched polymers as starting materials, this review discusses the kind of structural modifications that these polymers were subjected to for preparing nanocarriers of low toxicity, high encapsulating capacity, specificity to certain biological cells and transport ability under different environment conditions. Due to the great number of external groups of hyperbranched polymers either functionalization or multifunctionalization can occur, providing products that fulfill one or more of the requirements that an effective drug carrier should exhibit. Thus, hyperbranched polymers will play a significant role in the future development of new biomedical devices for the treatment of human diseases.