Masoud Mozafari’s research while affiliated with University of Oulu and other places

Bioceramics: Status in Tissue Engineering and Regenerative Medicine (Part 2) presents recent advancements in biocompatible ceramics and bioactive glasses, emphasizing their expanding applications in hard and soft tissue engineering. This book explores innovative manufacturing techniques like 3D printing and additive manufacturing and examines the therapeutic potential of bioceramics in areas such as bone regeneration, microbial infection management, wound healing, and cancer treatment. It also discusses current challenges, clinical applications, and future research directions. This book is a valuable resource for those developing biocompatible materials for medical applications. Key Features: - Comprehensive overview of bioceramic and bioactive glass applications in tissue engineering. - In-depth analysis of manufacturing techniques, including 3D printing and additive manufacturing. - Insights into clinical challenges, preclinical assessments, and future perspectives in regenerative medicine.

INTRODUCTION: The inflammatory response triggered by orthopedic devices results in the generation of reactive oxygen species (ROS) and a decrease in pH, accelerating the corrosion rate of Mg implants. To address corrosion challenges, various strategies are explored, including alloying with zinc and calcium elements and surface modifications. Plasma electrolytic oxidation (PEO) emerges as a promising technology, forming porous MgO coatings on Mg surfaces [1]. The electrolyte composition and the incorporation of additives not only affect coating characteristics but also influence the thickness and porosity of PEO coatings, collectively playing crucial roles in determining and preventing corrosion [2]. This study underscores the potential use of additives with ROS-scavenging properties, such as manganese-based additives in the PEO electrolyte, and the synthesis of MgO-Mn3O4 coatings on Mg-Zn-Ca alloy, as a means to mitigate corrosion rates, especially in inflammatory conditions. EXPERIMENTAL: In this study, PEO coatings incorporating Mn3O4 were fabricated on Mg-Zn-Ca substrate using two distinct methods: the introduction of KMnO4 salt and the inclusion of Mn3O4 nanoparticles in the electrolyte composition. In the first approach, composite coatings were chemically synthesized within the plasma microdischarge area, while the second route involved physical processes through electrophoretic adsorption. The electrochemical and immersion corrosion tests were conducted under simulated normal conditions using a PBS solution (pH 7) and under inflammatory conditions, achieved by introducing H2O2 and HCl (pH 5.2) into the PBS solution. RESULTS AND DISCUSSION: The experimental results showed that the inclusion of KMnO4 into electrolyte led to a reduction in voltages, while Mn3O4 resulted in an elevation in process voltages, directly impacting the structural characteristics of the coatings. Importantly, incorporating these additives decreases surface porosity and increases PEO coating thickness. Electrochemical and immersion corrosion tests, conducted under both simulated normal and inflammatory conditions, underscored the vulnerability of uncoated Mg-Zn-Ca alloy to corrosion, particularly in inflammatory settings (with corrosion rates increasing from approximately 2 to 16 mm·y-1). Notably, the composite PEO coatings, incorporating Mn3O4 nanoparticles, displayed superior corrosion performance. This superiority manifested as a significant decrease in corrosion current density and an increase in total impedance resistance compared to basic PEO coatings. For instance, potentiodynamic polarization results indicated a substantial reduction in corrosion current density, decreasing from 73.9 μA·cm-2 for basic PEO coatings to 5.5 μA·cm-2 for Mn3O4-incorporated PEO coatings. The enhanced performance was attributed to the catalytic activity of Mn3O4 in scavenging H2O2 in simulated inflammatory conditions, as well as the greater thickness and lower porosity of the composite coatings compared to basic PEO. Collectively, these features hindered the penetration of corrosive agents to the substrate. Moreover, the coatings showed a controlled release of Mn ions into the surrounding environment within a safe concentration range for the human body. CONCLUSIONS: These findings suggest that PEO coatings incorporating Mn3O4 present promising protective solutions for Mg implants, showcasing improved corrosion behavior associated with inflammation.

Biodegradable magnesium alloys for orthopedic bone fixation have been introduced for various fields of application. The corrosion resistance of magnesium implants weakens in physicochemical environments and is further compromised during post-implantation inflammation. In this study, Mn3O4-incorporated plasma electrolyte oxidation (PEO) coatings were developed on Mg-Zn-Ca substrate through two approaches: the addition of KMnO4 salt and the inclusion of Mn3O4 nanoparticles into the electrolyte composition. Incorporating additives into electrolytes led to a reduction in surface porosity and an increase in coating thickness in both synthesis approaches. The electrochemical and immersion corrosion tests were conducted under simulated normal conditions and inflammatory conditions, where inflammatory solutions were prepared with the addition of hydrogen peroxide (H2O2) and hydrochloric (HCl) acid. Both corrosion studies revealed that inflammation significantly increased the corrosion rate of the uncoated Mg-Zn-Ca biomaterial, escalating from approximately 2 mm·y-1 to 16 mm·y-1. Moreover, corrosion studies showed that the composite PEO coatings, incorporating Mn3O4 nanoparticles (MnPR-PEO), demonstrated superior corrosion performance among all coated samples. Potentiodynamic polarization results indicated a substantial reduction in corrosion current density, decreasing from 73.9 μA·cm-2 for basic PEO coatings to 5.5 μA·cm-2 for MnPR-PEO coatings. The improved performance of Mn3O4-incorporated PEO coatings, attributed to their catalytic H2O2 scavenging, suggests promise for magnesium implants, offering enhanced corrosion resistance and potential biomedical application benefits.

The continuing wave of technological breakthroughs and advances is critical for engineering well-defined materials, particularly biomaterials, with tailored microstructure and properties. Over the last few decades, controlled radical polymerization (CRP) has become a very promising option for the synthesis of precise polymeric materials with an unprecedented degree of control over molecular architecture. Atom Transfer Radical Polymerization (ATRP), one of the most robust and efficient CRPs, has been at the forefront of the synthesis of well-defined polymers with controlled/predetermined molecular weights, polydispersity, topology, composition, and site-specific functionality. ATRP has been leveraged to prepare a wide range of polymers with properties tailored for a number of biomedical applications. Furthermore, ATRP can also be utilized to introduce stimuli-responsive properties into the chemical structure of polymers. Moreover, the degradation behavior of ATRP-derived polymers can be tailored by incorporating chemical bonds susceptible to hydrolysis or proteolysis. This strategy allows the design of degradable polymers for in vivo applications. This review summarizes the recent advances in ATRP for the design of functional materials and techniques implemented to advance the biomedical field, such as surface modification and functionalization. Additionally, the latest applications and progress of ATRP-derived materials in various biomedical arenas such as drug delivery, tissue engineering, bioimaging, and biosensing are reported. Lastly, the current limitations and future perspectives of ATRP-derived biomaterials are carefully discussed to support further improvement of their properties and performance for translatability into the clinic. Moving forward, there is a need for further development of ATRP to align with green chemistry principles. This entails exploring the use of renewable monomers, environmentally friendly and nontoxic solvents, as well as metal-free and biocompatible catalysts. Additionally, researchers should thoroughly investigate the bioactivity, biodegradation behavior, and in vivo fate of ATRP-derived polymers and polymer conjugates before considering their translation into clinical applications.

Physicians encounter significant challenges in dealing with large diaphragmatic defects in both pediatric and adult populations. Diaphragmatic hernias, such as Morgagni, Bochdalek, and Hiatus hernias, can result in congenital lesions that are often undiagnosed until the appearance of symptoms (bleeding, anemia, and acid reflux). Therefore, substantial potential exists for developing tissue‐engineered constructs as novel therapeutic options in clinics. Recent research indicates promising mid‐term performance for both natural and synthetic materials. However, studies exploring their application in diaphragm regeneration are limited and remain in the early research stages. Additionally, further investigation is required to address the constraints in human tissue supply for clinical implementation. This article comprehensively reviews the role of biomaterials in diaphragmatic tissue repair and regeneration. It emphasizes biomaterials, including biomimetic polymers used in technological solutions. This summary will enable researchers to critically assess the capability of existing natural biomaterials as essential tissue‐engineered patches for clinical use.

Highlights In the world of biomedical breakthroughs, Rice University bioengineer Omid Veiseh and his team are making waves with their recent publication in Nature Biomedical Engineering (2023) (Mukherjeeet al., Nat Biomed Eng. 7:867–886, 2023). This study is a pivotal step in our fight against fibrosis, an issue that has long hindered medical progress. Their pioneering research isn’t just a scientific milestone; it’s a game-changer in how we tackle tissue scarring. Veiseh and his team have introduced an innovative method that allows for rapid testing of various materials within living organisms. By employing cellular barcoding and cutting-edge sequencing techniques, they’ve accelerated the assessment of multiple hydrogels. As we delve deeper into the specifics of this groundbreaking study, we uncover not just scientific insights, but the potential to revolutionize how we conceptualize and utilize biomaterials. This discussion isn’t merely about research methods; it’s about the ray of hope and boundless opportunities this study illuminates across the spectrum of biomaterials science.