Journal of biomedical materials research. Part B, Applied biomaterials最新文献

Titanium surfaces treated with cold atmospheric plasma exhibit enhanced wettability, cell adhesion, and surface energy; however, these beneficial effects tend to diminish over time due to aging-related changes caused by surface recontamination and the gradual loss of reactive species. This study investigates the influence of surface temperature during cold atmospheric plasma (CAP) treatment on the aging behavior of titanium, with a focus on time-dependent changes in physicochemical properties and biological responses. Titanium samples were treated with CAP at controlled surface temperatures of 40°C, 100°C, and 200°C. Treatment at 100°C and 200°C increased surface roughness, with more rounded peaks observed at 200°C. While wettability initially improved after treatment, it gradually declined over time, with the 200°C-treated samples exhibiting the smallest reduction. Biological assays revealed enhanced cell adhesion on surfaces treated at 100°C and 200°C, with scanning electron microscopy (SEM) showing filopodia formation and cell spreading. The Live/Dead assay confirmed improved cell viability on these surfaces. The AlamarBlue assay indicated that surfaces treated at 40°C and 100°C initially supported the highest cell proliferation, while the 200°C-treated samples maintained the most stable proliferation levels over a 15-day aging period. These findings underscore the impact of surface aging on biomedical device performance, highlighting its influence on the biological response. CAP treatment at 200°C provides durable surface modifications that preserve Ti biocompatibility over time, emphasizing the potential of advanced surface treatments to enhance the longevity and functionality of Ti-based biomedical implants.

Traumatic extremity injuries suffer a high probability of infection and often amputation due to contamination and delays in treatment. Military service members are predisposed to injury while engaged in conflict, yet current military adherence to antibiotic administration protocols following traumatic injury is lacking. Moreover, systemic antibiotic prophylaxis might not effectively eradicate biofilm throughout the wound site. Previously, an antibiotic wound gel was created to address current limitations of prophylactic antibiotic treatment in austere environments, particularly the battlefield, by offering a simple solution to control the release of tobramycin over a one-week period. We hypothesized that tobramycin eluted from the gel would effectively manage biofilm-related infection when tested in a large animal model of traumatic long-bone injury. Sheep were either treated with tobramycin-loaded gel or gel alone, and the reduction in bioburden was determined by quantifying tissue and inoculation substrates after a one-week period. Results indicated the wound gel was effective at managing biofilm in this model, with no detectable growth observed in tissues collected from treated animals. Further, the antibiotic-loaded wound gel significantly reduced the severity of the inflammatory response in the surrounding tissue. Biofilm presence was confirmed in scanning electron and light microscopy images of tissues treated with gel alone. Additionally, reactive bone growth, a characteristic of biofilm infection, was consistently observed in all untreated animals but appeared effectively managed in those treated with the antibiotic wound gel. Localized delivery of a broad-spectrum antibiotic from a controlled-release gel can improve adherence to antibiotic administration guidelines and has a greater potential to stabilize biofilm-contaminated wound sites quickly after injury while also mitigating a severe inflammatory response.

Clear aligners have revolutionized orthodontic treatment, yet concerns are rising about microplastics (MPs) and nanoplastics (NPs) released from these devices through mechanical wear and chemical degradation. Once ingested, these particles may undergo structural and chemical transformations in the gastrointestinal tract, particularly under acidic gastric conditions. Despite growing environmental and toxicological awareness, the degradation patterns of aligner materials remain largely unexplored. This study evaluated the acid-induced degradation and elemental release of thermoformed (TFA) and direct-printed (DPA) aligners in a simulated gastric environment. TFA (Invisalign SmartTrack) and DPA (Graphy TC-85DAC) samples were exposed to hydrochloric acid (pH 2). Surface acid-induced degradation was monitored using atomic force microscopy (AFM) over 60 min, while elemental release was quantified using inductively coupled plasma mass spectrometry (ICP-MS) following acid digestion on 0.5 M HCl leachates after 7 days. TFA rapidly disintegrated into an amorphous gel, preventing AFM imaging at pH 2. DPA maintained integrity and showed progressive roughening: RMS roughness rose from 10.06 to 10.97 nm (+ 9%; p < 0.001), mean roughness from 7.85 to 8.49 nm (+ 8%; p = 0.002), and maximum height from 68.31 to 76.51 nm (+ 12%; p = 0.038). ICP-MS of digested matrices revealed distinct elemental fingerprints: TFA was dominated by Sn (33.42 mg/kg), K (21.35 mg/kg), and Na (13.34 mg/kg); DPA by Ca (36.63 mg/kg), Na (11.87 mg/kg), and Fe (3.2 mg/kg). In 7-day 0.5 M HCl leachates, TFA released Sb 0.13 and Sn 0.09 mg/kg, whereas DPA showed Sb 0.03 and Sn 0.11 mg/kg; DPA leachates were richer in Ca (7.57 mg/kg) and Fe (1.57 mg/kg). DPA exhibited quantifiably slower acid erosion than TFA and distinct elemental release profiles at longer extraction, supporting greater acid-phase stability of DPA and providing elemental markers to trace aligner-derived particles. The results pertain to Invisalign SmartTrack and Graphy TC-85DAC and should not be generalized to all thermoformed or 3D-printed aligners. These findings emphasize the need for biostable, environmentally safer materials in orthodontics, especially considering the ingestion and systemic distribution of MPs.

Good bond strength between fiber-reinforced posts (FRPs) and root dentin is essential for successful rehabilitation of endodontically treated teeth. 45 human premolar teeth were divided into three main groups (n = 15) based on bonding agent use: no bonding (control), light-cured (LC), and dual-cured (DC). Each group was further split by cement type: self-adhesive resin cement, bioactive resin cement, and core build-up material, totaling nine subgroups. The teeth were sectioned perpendicularly to the root surface to obtain two middle-root slices. After thermocycling, the push-out bond strength (PBS) test was performed and data were statistically analyzed with the ANOVA test followed by the post hoc Tukey test. Failure modes were examined under a stereomicroscope and statistically evaluated using the χ² test. There was a significant difference in the PBS between test groups (p < 0.0001*). In control groups, core build-up material (Control/LZ = 7.6 ± 3.4 MPa) had significantly lower PBS than the rest of the groups, except Control/AB = 9.9 ± 3.3 MPa. The application of bonding agents significantly increased bond strength for bioactive cement (LC/AB = 14.8 ± 4.8 MPa and DC/AB = 17.7 ± 4.5 MPa) and core build-up material (LC/LZ = 20.4 ± 6.4 MPa and DC/LZ = 16.4 ± 3.8 MPa). Notably, self-adhesive resin cement achieved statistically similar PBS even without the application of bonding agent (Control/RX = 13.6 ± 3.1 MPa, LC/RX = 17.4 ± 5.5 MPa, and DC/RX = 17.0 ± 5.8 MPa). Self-adhesive resin cement can bond effectively to root dentin without additional bonding agents. However, bioactive and core build-up cements need bonding agents for optimal performance, highlighting the need to tailor bonding strategies to the specific cement used. Bonding FRPs to intra-radicular dentin was always a challenge. A strong bond to root dentin is an important factor to ensure the success and longevity of post and core restorations. This study provides great evidence for the significant influence of adhesive systems and resin cements on the bond strength of FRPs to root dentin. Using this study, clinicians will perform an informed choice of restorative materials for each clinical situation and select the best adhesive/cement combo to achieve good bond strength.

Three-dimensional (3D) bioprinting is transforming the delivery of active pharmaceutical compounds and regenerative medicine by enabling patient-specific solutions that enhance treatment efficacy and safety. This review explores recent advancements in 3D bioprinting for targeted therapy, focusing on its ability to fabricate complex delivery systems of drugs, cells, and various biomolecules with controlled and sustained release profiles. By leveraging bioinks with tunable properties, 3D bioprinting allows for localized drug administration, reducing systemic side effects while improving bioavailability. Additionally, in situ 3D bioprinting facilitates the direct deposition of therapeutic agents at the site of injury or disease, enhancing precision medicine approaches and supporting tissue regeneration. The integration of biocompatible bioinks and nanomedicines minimizes toxicity, enhances drug retention, reduces adverse effects, and enables personalized treatments, significantly improving therapeutic outcomes and, in some cases, improving pharmacokinetics. Despite these advancements, challenges remain in obtaining ideal biomaterial properties, post-printing modifications, printability, and biodegradability, which are critical for clinical translation. Addressing these barriers will be key to expanding the application of 3D bioprinting in precision medicine. This review provides insights into the recent pre-clinical progress, current clinical milestones, limitations, and future directions of 3D bioprinted delivery systems of active pharmaceutical compounds, highlighting their potential to revolutionize patient-centered therapies.