Bioresorbable Metals for Cardiovascular and Fracture Repair Implants

The potential of bioresorbable metals to revolutionize current and future medical devices fascinates researchers. Magnesium, iron, and zinc have been thoroughly studied for the treatment of cardiovascular diseases or to repair fractures. Iron was the first type of metal being researched and introduced in biomedical applications. Magnesium is the most studied one, it has been tested by clinical trials and commercially available products have been already developed. The interest in zinc has recently emerged and is continuously growing. This chapter offers an overview of the role that Mg, Fe, and Zn are playing advancing the evolution of bioresorbable implants.

Study of the Influence of PCL on the In Vitro Degradation of Extruded PLA Monofilaments and Melt-Spun Filaments

This work presents the effect of a melt-spinning process on the degradation behavior of bioresorbable and immiscible poly(d,l-lactide) (PLA) and polycaprolactone (PCL) polymer blends. A large range of these blends, from PLA90PCL10 (90 wt% PLA and 10 wt% PCL) to PLA60PCL40 in increments of 10%, was processed via extrusion (diameter monofilament: ∅ ≈ 1 mm) and melt spinning (80 filaments: 50 to 70 µm each) to evaluate the impact of the PCL ratio and then melt spinning on the hydrolytic degradation of PLA, which allowed for highlighting the potential of a textile-based scaffold in bioresorbable implants. The morphologies of the structures were investigated via extracting PCL with acetic acid and scanning electron microscopy observations. Then, they were immersed in a Dulbecco’s Modified Eagle Medium (DMEM) media at 50 °C for 35 days and their properties were tested in order to evaluate the relation between the morphology and the evolution of the crystallinity degree and the mechanical and physical properties. As expected, the incorporation of PCL into the PLA matrix slowed down the hydrolytic degradation. It was shown that the degradation became heterogeneous with a small ratio of PCL. Finally, melt spinning had an impact on the morphology, and consequently, on the other properties over time.

In-Office Corticosteroid Placement in the Management of Chronic Rhinosinusitis

Objectives: Corticosteroids represent one of the mainstays of medical management of chronic rhinosinusitis (CRS) in both locally acting topical and systemic derivations. The application of topical corticosteroids is limited by a variety of factors including patient compliance, positioning, and nasal anatomy. Systemic corticosteroids confer a risk of medical complication that restricts their ability to be used repeatedly. The objective of this publication is to review the evolution of the in-office intranasal placement of corticosteroids in the management of CRS. The efficacy, outcomes, and safety of a variety of corticosteroid-containing devices meant to be placed in an office setting are reviewed. Methods: Pertinent literature was reviewed and summarized beginning with the earliest reports of direct intralesional injection of corticosteroids up through manufactured modern-day bioresorbable implants that contain corticosteroids. Results: The utilization of in-office placement of corticosteroid-containing material and implants has rapidly evolved since the concept was introduced, particularly in the last decade. Modern-day corticosteroid-eluting implants are reliably placed in the office, yield results across a range of objective and subjective outcomes, may decrease the need for revision endoscopic sinus surgery, and have a favorable safety profile. Conclusions: In-office placement of corticosteroid-containing stents are a viable treatment option for select patients, particularly those wishing to avoid revision surgery, and should be considered an important adjunct for treatment of refractory CRS in an otolaryngologist’s armamentarium.

Triple-Shape Memory Behavior of Modified Lactide/Glycolide Copolymers

The paper presents the formation and properties of biodegradable thermoplastic blends with triple-shape memory behavior, which were obtained by the blending and extrusion of poly(l-lactide-co-glycolide) and bioresorbable aliphatic oligoesters with side hydroxyl groups: oligo (butylene succinate-co-butylene citrate) and oligo(butylene citrate). Addition of the oligoesters to poly (l-lactide-co-glycolide) reduces the glass transition temperature (Tg) and also increases the flexibility and shape memory behavior of the final blends. Among the tested blends, materials containing less than 20 wt % of oligo (butylene succinate-co-butylene citrate) seem especially promising for biomedical applications as materials for manufacturing bioresorbable implants with high flexibility and relatively good mechanical properties. These blends show compatibility, exhibiting one glass transition temperature and macroscopically uniform physical properties.