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International Journal of Bioprinting 3D printing innovations against infection

Correia et al. prepared tricalcium phosphate (TCP)/ 4.1.2. Antimicrobial drug loading into
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sodium alginate (SA) scaffolds using rapid prototyping 3D-printed scaffolds
(RP) technique, and silver nanoparticles (AgNPs) were In addition to inorganic substances, organic agents such
introduced into the scaffolds through two different as antibiotics, antimicrobial peptides, and phages find
methods. The results indicated that the composite scaffolds extensive applications in the prevention and treatment
directly doped with AgNPs exhibited suitable mechanical of periprosthetic infections (Table 1). In a study utilizing
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properties and biocompatibility, as well as bactericidal a canine model of humeral defect, Turner et al.
activity, rendering them particularly well-suited for bone demonstrated that the combination of tobramycin with
tissue regeneration. The structural integration of AgNPs calcium sulfate significantly augmented bone tissue
within this 3D scaffold effectively addresses bacterial production, elevated local antibiotic concentrations, and
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infection issues, presenting a viable solution to overcome extended antibiotic release. Furthermore, Logoluso et al.
limitations associated with implants. Li et al. employed employed an innovative coating technique integrating
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3D printing to fabricate porous polycaprolactone (PCL) calcium sulfate and hydroxyapatite with gentamicin
scaffolds and achieved nanosilver (nAg) enrichment on the or vancomycin, which were subsequently loaded into
bionic surface through polydopamine (PDA) modification. orthopedic implants (comprising 7% calcium sulfate and
The experimental findings demonstrated that the nAg/ 13% hydroxyapatite). These implants were deployed in
PDA/PCL scaffold effectively reduced bacterial adhesion 20 hip or knee revision prosthetic surgeries, with a 1-year
and colonization. Moreover, the scaffold exhibited superior follow-up. Encouragingly, the study results revealed
performance in the accumulation of mineralized bone a lack of infection recurrence in 95% of the patients.
tissue after 8 weeks of in vivo implantation (Figure 4C). This underscores the effectiveness of absorbable bone-
This research approach mirrors that of Deng et al., who conducting antibiotic carriers in shielding postoperative
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successfully immobilized AgNPs uniformly on the surface implants from the risk of bacterial adherence.
of 3D-printed polyether ether ketone (PEEK) orthopedic Furthermore, 3D printing technology exhibits
scaffolds using a catecholamine-silver chemical reduction significant potential in delivering antibiotics for the
method. Subsequently, a quantitative study employing treatment of prosthetic infections. Through this technology,
bacterial kinetic profiles was conducted to evaluate it becomes feasible to fabricate personalized prostheses
the antimicrobial effect of the materials. The results with an embedded antibiotic release system, facilitating
indicated that the AgNPs-decorated scaffolds promoted sustained antibiotic release and thereby mitigating the risk
cell proliferation and increased alkaline phosphatase of infection recurrence. 115,116 In the treatment of chronic
activity compared to unmodified pure PEEK scaffolds, bone infections, a common approach involves systemic
implying that Ag-decorated 3D PEEK scaffolds exhibit and local administration of antibiotics to the affected area
significant antimicrobial effects against both Gram- using PMMA bone cement. However, the high antibiotic
negative and Gram-positive bacteria. PEEK stands concentrations required by bacteria in biofilms pose a
out as a preferred alternative for orthopedic implant challenge, as the elevated stoichiometry of locally delivered
materials due to its excellent mechanical properties and antibiotics can hinder PMMA polymerization, rendering it
biocompatibility. Studies have demonstrated that porous unsuitable for the targeted delivery of specific antibiotics.
PEEK scaffolds printed with 3D technology are most In a study by Inzana et al., 3D printing was successfully
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favorable for osteoblast adhesion, proliferation, and employed to produce calcium phosphate scaffolds
osteogenic differentiation. Those with relatively large (CPSs) containing rifampicin and vancomycin for the
pores (PEEK-450 and PEEK-600) are more suitable for treatment of implant-associated S. aureus bone infections
promoting cell proliferation (Figure 4D). Considering in a mouse model of staphylococcal bone infection. The
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the electrophysiological environment of normal bone finding revealed a significant reduction in bacterial load
tissue, which aids in inducing stem cell differentiation with CPS treatment compared to PMMA containing
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and inhibiting bacterial adhesion and activity, Li et al. rifampicin and vancomycin. Moreover, in mice receiving
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innovatively developed a self-promoting electroactive CPS with sustained release of rifampicin and vancomycin,
mineralized scaffold (sp-EMS). Through electrochemical 50% of bone bacterial cultures yielded negative results.
reactions, sp-EMS successfully achieved osteogenic This indicates that the 3D-printed CPS could co-deliver
differentiation of stem cells. Additionally, the electroactive rifampicin and vancomycin, achieving outcomes not
interface provided by sp-EMS inhibited bacterial adhesion attainable with PMMA and markedly enhancing the
and activity through the generation of electrochemical prognosis of implant-associated osteomyelitis. Zhou et
products. The scaffold exhibited significant efficacy in the al. successfully employed 3D printing technology to
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treatment of bone defects (Figure 4E). manufacture a novel PCL composite scaffold and coated

Volume 10 Issue 4 (2024) 132 doi: 10.36922/ijb.2338