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Zhang, et al.
A B

C

Figure 4. DLP 3D printing of drug delivery system: (A) A range of injectable microhydrogels encapsulating drugs , (B)
[73]
functionalized nerve conduits , (C) microstructure of 3D printed tablets .
[44]
[75]
6 Challenges and future perspectives Metal, glass, and ceramic products can be
obtained through printing and sintering. More
As one of the 3D printing techniques, DLP-based and more materials are developed in DLP-based
3D printing inherits the advantages of fabricating 3D printing . For example, the materials include
[76]
complex personalized productions. Meanwhile, functionalized materials, initiator-free materials,
this technique has its own characteristics of high and non-toxic initiators. Although DLP 3D
precision, fast speed, and mild condition. Thus, printing technology has made advancements,
on the basis of conventional medical applications, it still takes some deficiencies . The materials
[12]
DLP-based 3D printing can improve the accuracy choice is limited to only photosensitive polymers.
and cell livability of the fabricated products. Many excellent materials cannot be printed
As a result, the medical models manufactured directly. They are required to be combined with
by DLP 3D printing can better simulate the photosensitive polymer or chemical modified
real states or locate implants. The devices with by photosensitive groups. To accelerate the
precision structures are more sensitive. The photopolymerization, photoinitiator, mostly
microstructures of tissues can be accurately having toxicity, is required to be added in the
built to obtain engineered tissues and organs for mixed inks. When the light is projected from
organ transplantation, disease research, and drug top-down in DLP-based 3D printer, the materials
development. Furthermore, DLP 3D printing are not extruded by nozzles, but pre-filled the
can manufacture predesigned microstructures of container. It may raise the concerns of materials
pharmaceutical and accurately control the position wastage and cost increases. With the development
and doses of drugs. of 3D printing technology, there will be more
The printing equipment and materials are the equipment and materials emerging in the future.
foundation of applications in medicine, which are There is forced onto the cells as well when the
increasingly developed. Some breakthroughs have printing platform is lowered or the platform is
been made. Continuous liquid interface printing separated from the printed surface. The repeated
improved the resolution and speed of DLP 3D lifting of printing platform should be avoided
printing . Using tomographic reconstruction or reduced during printing. More studies are
[20]
can fabricate a volumetric construct at once . required to reduce the separating force between
[21]
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