[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Chitin and chitosan: Properties and applications

Spurred by recent progress in materials chemistry and drug delivery, stimuli-responsive devices that deliver a drug in spatial-, temporal- and dosage-controlled fashions have become possible. Implementation of such devices requires the use of biocompatible materials that are susceptible to a specific physical incitement or that, in response to a specific stimulus, undergo a protonation, a hydrolytic cleavage or a (supra)molecular conformational change. In this Review, we discuss recent advances in the design of nanoscale stimuli-responsive systems that are able to control drug biodistribution in response to specific stimuli, either exogenous (variations in temperature, magnetic field, ultrasound intensity, light or electric pulses) or endogenous (changes in pH, enzyme concentration or redox gradients).

Stimuli-responsive nanocarriers for drug delivery

Hydrogels for tissue engineering: scaffold design variables and applications.

Hydrogels for tissue engineering.

Conformation–function relationships for the comb-shaped polymer pOEGMA

Plasmonic biocompatible silver–gold alloyed nanoparticles

Since the first report of 3D printed biodegradable structures by stereolithography, vat photopolymerization has shown great potential in the fabrication of medical implants and devices. Despite its superior printing quality and manufacturing speed, the development of biodegradable devices by this technique remains challenging. This results from the conflicting viscosity requirements for the printing resins, i.e., low viscosity is required for high‐resolution 3D printing, whereas high viscosity is often needed to provide high mechanical strength. Recently emerging photopolymerization‐based 3D printing techniques, including heat‐assisted digital light processing (DLP) and volumetric printing, have brought new hope to the field. With its tolerance to high viscosity resins, heat‐assisted DLP enables the fabrication of complex, personalizes architectures from biodegradable photopolymers that are not printable by conventional printing techniques. On the other hand, volumetric printing, which abandons the layer‐by‐layer printing principle and thus circumvents the dependence on low viscosity resins, could be highly beneficial for the 3D printing of biodegradable devices. This perspective evaluates the key challenges associated with biodegradable photopolymers used in the 3D printing of medical implants and devices. One focuses on their chemical structures and physical properties and discusses future directions offered by these emerging techniques.

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Challenges and Opportunities in 3D Printing of Biodegradable Medical Devices by Emerging Photopolymerization Techniques

It is well established that micellar structures can form in non-aqueous solutions. The resulting nanostructures, commonly referred to as ‘reverse micelles’, are characterized by a polar core and hydrophobic shell. Such micelles have typically been generated from hydrophobically-modified polar branched polymers and evaluated as solubilizing agents for low molecular-weight anionic dyes. From these studies, critical elements, such as micelle composition and size, have been identified as being determinants of micellar behavior. In this manuscript, the synthesis and characterization of amphiphilic branched polymers that have been used in the preparation of reverse micelles are reviewed, with a particular focus on the factors dictating their ability to interact with hydrophilic guest molecules.

Reverse micelles from amphiphilic branched polymers

The purpose of this study was to evaluate in vivo a targeted pH-sensitive liposomal formulation tailored to promote the efficient intracellular delivery of 1-β-d-arabinofuranosylcytosine (ara-C) to human myeloid leukemia cells. Specifically, pH-sensitive immunoliposomes were obtained by anchoring a copolymer of dioctadecyl, N-isopropylacrylamide and methacrylic acid in bilayers of PEGylated liposomes (LP) and by coupling the whole anti-CD33 monoclonal antibody (mAb) or its Fab′ fragments. Their pharmacokinetic and biodistribution profiles were assessed in Balb/c and leukemic HL60-bearing immunodepressed (SCID) mice. In naive mice, nontargeted and pH-sensitive Fab′-LP had longer circulation times than LP with whole mAb. In SCID/HL60 (CD33+) mice, the pharmacokinetic and biodistribution profiles of LP and encapsulated ara-C were comparable between nontargeted and pH-sensitive Fab′-LP. In leukemic mice, only pH-insensitive, ara-C-loaded Fab′ induced prolonged survival times. The apparent absence of pH-sensit...

Jean-Christophe Leroux

Papers

Conformation–function relationships for the comb-shaped polymer pOEGMA

Plasmonic biocompatible silver–gold alloyed nanoparticles

Challenges and Opportunities in 3D Printing of Biodegradable Medical Devices by Emerging Photopolymerization Techniques

Reverse micelles from amphiphilic branched polymers

In Vivo Evaluation of pH-Sensitive Polymer-Based Immunoliposomes Targeting the CD33 Antigen