[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

3D printing alias additive manufacturing can transform 3D virtual models created by computer-aided design (CAD) into physical 3D objects in a layer-by-layer manner dispensing with conventional molding or machining. Since the incipiency, significant advancements have been achieved in understanding the process of 3D printing and the relationship of component, structure, property and application of the created objects. Because hydrogels are one of the most feasible classes of ink materials for 3D printing and this field has been rapidly advancing, this Review focuses on hydrogel designs and development of advanced hydrogel-based biomaterial inks and bioinks for 3D printing. It covers 3D printing techniques including laser printing (stereolithography, two-photon polymerization), extrusion printing (3D plotting, direct ink writing), inkjet printing, 3D bioprinting, 4D printing and 4D bioprinting. It provides a comprehensive overview and discussion of the tailorability of material, mechanical, physical, chemical and biological properties of hydrogels to enable advanced hydrogel designs for 3D printing. The range of hydrogel-forming polymers covered encompasses biopolymers, synthetic polymers, polymer blends, nanocomposites, functional polymers, and cell-laden systems. The representative biomedical applications selected demonstrate how hydrogel-based 3D printing is being exploited in tissue engineering, regenerative medicine, cancer research, in vitro disease modeling, high-throughput drug screening, surgical preparation, soft robotics and flexible wearable electronics. Incomparable by thermoplastics, thermosets, ceramics and metals, hydrogel-based 3D printing is playing a pivotal role in the design and creation of advanced functional (bio)systems in a customizable way. An outlook on future directions of hydrogel-based 3D printing is presented.

3D printing of hydrogels: Rational design strategies and emerging biomedical applications

Stereolithography is a solid freeform technique (SFF) that was introduced in the late 1980s Although many other techniques have been developed since then, stereolithography remains one of the most powerful and versatile of all SFF techniques It has the highest fabrication accuracy and an increasing number of materials that can be processed is becoming available In this paper we discuss the characteristic features of the stereolithography technique and compare it to other SFF techniques The biomedical applications of stereolithography are reviewed, as well as the biodegradable resin materials that have been developed for use with stereolithography Finally, an overview of the application of stereolithography in preparing porous structures for tissue engineering is given

A review on stereolithography and its applications in biomedical engineering

Background: A new type of microscope has been developed for acquiring cross-sectional images of living skin noninvasively. It takes advantage of the short temporal coherence of a broad-band light source to reject scattered light. Because this microscope is still in an early stage of development, its potential as a diagnostic tool in dermatology has not yet been determined. Objective: This study was designed to explore potential applications of optical coherence microscopy in dermatology. The aim was to investigate the structures in skin that can be seen without staining or using sophisticated image-processing methods. Methods: A prototype fiberoptic microscope was assembled that uses a 1,300-nm light-emitting diode as a light source. Scans were obtained from the skin on the index finger and forearm. Subsurface structures were identified based on knowledge of the anatomy of normal healthy skin. Results: Structures located as deep as 1 mm below the surface of the skin could be imaged with a resolution of about 10 μm in the axial and lateral dimensions. In optical slices taken perpendicular to the skin surface, the contours of the epidermal ridges and the bond ary between the epidermis and dermis were readily observed. Conclusions: The results of this study suggest that an optical coherence microscope may have value as a diagnostic tool for cases in which visualization of subcellular details is not required. The resolution, contrast and scanning speed of the microscopy need to be improved.

Subsurface Imaging of Living Skin with Optical Coherence Microscopy

https://hal.archives-ouvertes.fr/hal-02991710/document

3D Extracellular Matrix Mimics: Fundamental Concepts and Role of Materials Chemistry to Influence Stem Cell Fate

3D bioprinting of tissues and organs for regenerative medicine.

3D bioprinting of skin tissue: From pre-processing to final product evaluation.

First-line cancer chemotherapy has been prescribed for patients suffered from cancers for many years. However, conventional chemotherapy provides a high parenteral dosage of anticancer drugs over a short period, which may cause serious toxicities and detrimental side effects in healthy tissues. This study aims to develop a new drug delivery system (DDS) composed of double-walled microparticles and an injectable hydrogel for localized dual-agent drug delivery to tumors. The uniform double-walled microparticles loaded with cisplatin (Cis-DDP) and paclitaxel (PTX) were fabricated via coaxial electrohydrodynamic atomization (CEHDA) technique and subsequently were embedded into injectable alginate-branched polyethylenimine. The findings show the uniqueness of CEHDA technique for simply swapping the place of drugs to achieve a parallel or a sequential release profile. This study also presents the simulation of CEHDA technique using computational fluid dynamics (CFD) that will help in the optimization of CEHDA’s...

Double-Walled Microparticles-Embedded Self-Cross-Linked, Injectable, and Antibacterial Hydrogel for Controlled and Sustained Release of Chemotherapeutic Agents.

Our previous work demonstrated the uniform particle pattern formation on the substrates using electrical field guided electrospray deposition. In this work, we reported for the first time the fabri...

Wei Cheng Yan

Papers

3D bioprinting of tissues and organs for regenerative medicine.

3D bioprinting of skin tissue: From pre-processing to final product evaluation.

Double-Walled Microparticles-Embedded Self-Cross-Linked, Injectable, and Antibacterial Hydrogel for Controlled and Sustained Release of Chemotherapeutic Agents.

Electrical Field Guided Electrospray Deposition for Production of Gradient Particle Patterns.