Page 167 - IJB-9-2

International Journal of Bioprinting 3D Printing Multifunctional Orthopedic Biocoatings

effectiveness [1-3] . The careful choice and application of biopixels which combine characteristics of inkjet printing
coating materials at the implant interface are key to its and basic biological units. Ng et al. identified optimal
success. The incorporation of drugs or biofactors within droplet velocity and droplet volume to mitigate adverse
polymeric encapsulation on metallic implants not only impact on cell survivability and droplet splashing with
[46]
serves as a conduit for spatiotemporal bioagent [4-7] sub-nanoliter-based bioprinting . Vat polymerization
delivery but also provides surface modification properties (VP) is 3D printing process that uses UV light as a curing
to improve the biocompatibility and overall clinical mechanism for a desired object in a prefilled vat. Several
[47]
performance of the implant device [8-10] . researchers have conducted a comprehensive review of
the materials, process conditions, regulatory challenges,
Titanium and its alloys are widely used in orthopedic
implants for the past several decades [11-13] . Despite and future directions in VP toward tissue engineering
and regenerative medicine applications. Further, new
sterilization and aseptic procedures, bacterial infections VP strategies are discussed for in vivo regeneration and
associated with titanium-based orthopedic implantation drug screening therapeutics including biomaterial ink
are still a major challenge and cause implant failure [14-21] . formulations and VP system designs . Thus, it is evident
[47]
The main reason for implant surface vulnerability to that a multitude of biofabrication processes are available
infection is the formation of a surface biofilm, which based on the type of biomaterial and configuration of tissue
compromises the immune capability at the implant/tissue construct to be manufactured for a specific application.
interface [14,20-23] . At present, several methods are in place
to prevent implant-associated bacterial infections. They Our research group employs a customized 3D printing
involve incorporating antimicrobial agents into polymeric coating technique to uniformly deposit multilayers of
implant coatings, engineering polymeric coatings to polymeric formulations embedded with therapeutic
actively release tunable antimicrobial agents, and finally, agents [48-53] . In our previous work, basic inkjet printing was
altering the surface physiochemical properties of the utilized for polyester urethane urea coatings embedded
implant device [20,21,24-26] . Molecular mechanisms for drug with paclitaxel (Taxol) agent for cardiovascular stent
and growth factor elution have been studied to enhance applications. Similarly, different polymeric coatings
its adsorption behavior on a variety of substrates [27-31] . The were evaluated for their corrosion protection potential
effect of liquid-surface interactions impacting different on magnesium alloys for tracheal applications. Unlike,
applications has been widely studied using atomistic above-described simpler approaches, a retrofitted 3D
modeling [32-35] . According to Hetrick et al. , delivering printing system was utilized in this research which can
[21]
the antibiotic in a tunable manner at the implant site from deposit multilayered structures for 3D scaffolds and have
a polymeric surface coating is the preferred approach to in situ infiltration capability for specific growth factors,
improving the efficacy of conventional antibiotics against biomaterials and cell-laden media. Further, we synthesized
implant-associated bacterial infection. Loading antibiotics a unique ink formulation which includes both bone
into bioresorbable polymeric coatings have proven to be promoting and antibacterial agents simultaneously. These
effective in eliminating or reducing bacterial infection include nanoparticulates of amorphous calcium phosphate
associated with orthopedic implants [14,16,17,36-42] . (ACP) for promoting osseointegration and antibiotic
(vancomycin [VA]) to eliminate bacterial infections in
Different disposition techniques have been utilized orthopedic implant applications. The implementation
for the coating of biomedical devices with each having of multilayered coatings has proven to be effective in
their own respective advantages and disadvantages. Some providing tunable release of different growth and healing
of the prominent processes used in the bioprinting field agents when encapsulated within bioresorbable polymeric
include inkjet printing, stereolithography, laser-induced thin films [54-56] . In the field of polymer deposition, inkjet
[43]
forward transfer, and extrusion deposition. Jiang et al. technology has several advantages making it an ideal
[57]
discussed different types of extrusion heads and material technique for coating implant devices. The problems
compositions using pneumatic and mechanical actuation associated with conventional polymer/drug loading
mechanisms. Similarly, Zhuang et al. presented a facile coating techniques have been discussed extensively by de
[44]
bioprinting strategy that combines the rapid extrusion- Gans et al. . They range from the inability to vary drug
[57]
based bioprinting technique with an in-built ultraviolet distribution in a controlled manner for a specific drug
(UV) curing system to facilitate the layer-by-layer UV loading profile, variations, and inconsistency in drug
curing of bioprinted photocurable GelMA-based hydrogels. concentration from device to device, recurrent webbing
Li et al. have outlined the use of inkjet printing for between the struts, and the inability to control the local
[45]
drug development, scaffold building, and cell depositing density of the drug. The use of the drop-on-demand inkjet
in their review article. They elucidate the concept of printing eliminates issues associated with the conventional

Volume 9 Issue 2 (2023) 159 https://doi.org/10.18063/ijb.v9i2.661