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International Journal of Bioprinting 3D printing innovations against infection

employing 3D extrusion printing to produce filaments Furthermore, nitric oxide (NO) has been explored for its
with varying concentrations of thermoplastic polyurethane ability to inhibit microbial growth. In a study organized by
(TPU) and tetracycline hydrochloride (TC). Subsequently, Carlsson et al., acidified inorganic nitrite was employed
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FDM 3D printers were utilized to craft catheter structures. to generate NO, which was then impregnated into the
The catheters containing TC exhibited a notable catheter in gaseous form. The results demonstrated that
inhibitory effect on S. aureus, demonstrating a consistent NO effectively inhibited the growth of microorganisms,
antimicrobial efficacy in release studies (Figure 5A). such as E. coli, and prevented the formation of biofilms.

Moreover, given that the pathogenesis of CAUTI Besides that, a new concept of on-demand fouling release
involves various virulence factors such as toxins, flagella, from catheters through mechanical disruption and removal
adhesins, and cell signaling mechanisms (quorum sensing, of biofilm has been proposed to realize an active response
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QS), the development of a catheter that not only prevents of the inner surface of the catheter to external stimuli
biofilm deposition but also reduces QS signaling would be (Table 2). The design incorporates hydraulic and pneumatic
a preferable option. Metronidazole has been reported elastomer actuation for selective release of surface strain
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to inhibit several group-sensing-mediated virulence within the catheter lumen. A proof-of-concept prototype,
factors associated with UTIs. Archana et al. employed a constructed using 3D printing and other techniques,
pressure-assisted microinjector technique to successfully effectively demonstrated the release of crystalline biofilm
3D-print catheters, impregnating them with secnidazole, of Proteus mirabilis on a strained surface (Figure 5D). This
an antimicrobial drug from the 5-nitroimidazole class lays the foundation for pioneering catheter technologies
effective against anaerobic Gram-positive and negative aimed at efficiently managing infectious biofilms, offering
bacteria. The results demonstrated that this 3D-printed a complementary approach to conventional methods.
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catheter disrupted biofilms and inhibited all group- 4.3. Innovative 3D-bioprinted skin patches and
sensing-mediated virulence factors produced by two wound dressings for infection prevention
significant causative agents of UTIs. This innovative Tissue injury and wound healing represent critical aspects
approach addresses biofilm formation and targets key of clinical medicine, encompassing intricate physiological
virulence factors, presenting a promising strategy in the and biochemical processes necessitating prompt and
prevention of CAUTIs (Figure 5B). effective intervention. In this context, the significance of
4.2.3. Other biomaterials wound excipients cannot be overstated. Wound excipients
In addition to metallic silver coatings, metallic copper play a pivotal role in mitigating infection risks, fostering
coatings are widely applied in medical devices and optimal wound healing, and enhancing the overall
equipment by virtue of their potent antimicrobial quality of life for patients. This is achieved through the
properties. The antimicrobial efficacy of copper coatings provision of suitable wound protection, establishment of
lies in the release of copper ions, which disrupt microbial a conducive moist healing environment, implementation
cell membranes and DNA, effectively inhibiting the growth of antimicrobial control, and proficient management of
and reproduction of microorganisms. One research excretions. Additionally, specific wound adjuvants exhibit
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observed that copper and silver coatings exhibited highly the capacity to minimize scarring and enhance wound
effective antimicrobial properties against microorganisms aesthetics, contributing to a comprehensive approach to
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like E. coli, with copper outperforming silver in this wound care. Consequently, healthcare professionals
regard. This highlights the significant advantage of meticulously choose appropriate wound excipients in
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copper coatings in preventing microbial attachment and clinical practice to ensure the success of wound treatment
biofilm formation. Silicone has emerged as a promising and to facilitate maximal patient recovery (Table 3).
biomaterial for catheterization applications owing to its Multifunctional 3D printing of wound dressing is an
mechanical strength, biocompatibility, and capacity to advanced manufacturing technology specifically designed
mitigate catheter encrustation. Kyser et al. successfully for emulating and reconstructing natural extracellular
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prepared 3D-printed silicone scaffolds incorporating matrix (ECM) of skin, employing biocompatible
Lactobacillus rhamnosus for urinary catheters. The scaffold materials embedded with antibacterial NPs and vascular
exhibited effective curing of silicone and integration endothelial growth factors. This innovative technology
with Lactobacillus rhamnosus, demonstrating robust has found applications in the creation of skin substitutes,
mechanical integrity. It displayed favorable outcomes in aiming to prevent or treat infection and enhance skin cell
terms of recovery from bacterial infections, production proliferation, adhesion, and differentiation (Figure 6A).
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of antimicrobial agents, and effectiveness against urinary In various in vitro studies, these engineered skin substitutes
pathogenic E. coli (Figure 5C). consistently demonstrate high cell viability. For instance, in

Volume 10 Issue 4 (2024) 137 doi: 10.36922/ijb.2338