Pilot study on serum C-reactive protein in pet rabbits: clinical usefulness

3D printed drug-eluting stents: Toward personalized therapy for airway stenosis

Airway stents are life-saving medical devices used to treat malignant or benign central airway stenoses. Unfortunately, these devices, typically manufactured from silicone alone and/or nitinol, can result in serious complications, such as stent migration, bacterial colonization, and tissue granulation, eventually forcing stent removal. Customized airway stents exhibit reduced migration and they can be tailored to address other complications by releasing drugs, such as the antibiotic levofloxacin and the antifibrotic drug nintedanib. Herein, the incorporation of these molecules in customized, bioresorbable 3D printed airway stents was investigated. Nintedanib (1.5 wt%) and levofloxacin (2.0 wt%) were incorporated in the polymer-based resin, which was used to 3D print tracheal stents with adequate mechanical and drug release properties. The drug-loaded stents were then deployed into rabbit tracheas and found to deliver the drugs locally with minimal systemic exposure. Drug activities were demonstrated by inhibition of bacterial colonization and reduced interleukin 8 (IL8) local expression. Although the application of these tracheal stents requires further exploration in larger animal models, this work paves the way for the rapid manufacturing of personalized medical devices with therapeutic functions.

Evolution from Bioinert to Bioresorbable: In Vivo Comparative Study of Additively Manufactured Metal Bone Scaffolds

Additively manufactured scaffolds offer significant potential for treating bone defects, owing to their porous, customizable architecture and functionalization capabilities. Although various biomaterials have been investigated, metals - the most successful orthopedic material - have yet to yield satisfactory results. Conventional bio-inert metals, such as titanium (Ti) and its alloys, are widely used for fixation devices and reconstructive implants, but their non-bioresorbable nature and the mechanical property mismatch with human bones limit their application as porous scaffolds for bone regeneration. Advancements in additive manufacturing have facilitated the use of bioresorbable metals, including magnesium (Mg), zinc (Zn), and their alloys, as porous scaffolds via Laser Powder Bed Fusion (L-PBF) technology. This in vivo study presents a comprehensive, side-by-side comparative analysis of the interactions between bone regeneration and additively manufactured bio-inert/bioresorbable metal scaffolds, as well as their therapeutic outcomes. The research offers an in-depth understanding of the metal scaffold-assisted bone healing process, illustrating that Mg and Zn scaffolds contribute to the bone healing process in distinct ways, but ultimately deliver superior therapeutic outcomes compared to Ti scaffolds. These findings suggest that bioresorbable metal scaffolds hold considerable promise for the clinical treatment of bone defects in the near future.

Does Venipuncture Increase Lymphedema by Triggering Inflammation or Infection? An Experimental Rabbit Ear Lymphedema Model Study

Background: Recent guidelines recommend avoiding venipuncture to prevent lymphedema for breast cancer patients. This study investigated whether single or multiple sterile venipuncture procedures develop a systemic inflammation or infection and increase lymphedema in the rabbit ear lymphedema model. Methods and Results: Eighteen New Zealand white female rabbits were included. The right ear lymphedema model was created by surgical procedure; then, rabbits were divided into three randomized groups. Single and multiple venipuncture procedures were applied at least the 60th day after surgery for Group I and II, respectively. Group III was a control group. C-reactive protein (CRP) and procalcitonin (PCT) levels were analyzed to determine inflammation and infection. Ear thickness measurements were applied using a vernier caliper to assess the differences in lymphedema between the ears. All rabbits were euthanized on the 90th day after surgery. Histopathological analysis was performed to evaluate lymphedema by measuring tissue thicknesses. Ear thickness measurements showed that ear lymphedema was developed and maintained with surgical operation in all groups (p < 0.05). There was no difference in the ear thickness measurements between and within-groups results (p > 0.05). CRP and PCT levels were below the lower detection levels in all groups. According to the differences of histopathological ear distances, there were significant differences within-groups for all groups (p < 0.05), and no differences were identified between groups (p > 0.05). Conclusion: This experimental study demonstrated that single or multiple sterile venipuncture procedures did not trigger infection or inflammation and did not exacerbate ear lymphedema in the rabbit ear lymphedema model.