Among various classes of biomaterials, the majority of non-centrosymmetric crystalline materials exhibit piezoelectric properties, i.e., the accumulation of charge in response to applied mechanical stress or deformation. Due to the growing interest in nanomaterials, piezoelectric nano-biomaterials have been widely investigated, leading to remarkable advancements throughout the last two decades. Piezoelectric properties, high surface energy, targeting properties, and intricate cell-material interactions render piezoelectric nanomaterials highly attractive for application in therapeutics as well as regenerative medicine. Herein, the major focus is to highlight the wide range of applications of piezoelectric nano-biomaterials in drug delivery, theranostics, and tissue regeneration. After a brief introduction to piezoelectricity, an overview is provided on the major classes of piezoelectric biomaterials as well as a description of the origin of biopiezoelectricity in different tissues and macromolecules. Subsequently, relevant properties and postfabrication strategies of nanostructured piezoelectric biomaterials are discussed aiming to maximize piezoresponse. Finally, recent studies on nano-piezoceramics and piezopolymers are presented, with specific focus on barium titanate, zinc oxide, and polyvinylidene fluoride.
Cementless fixation for orthopedic implants aims to obviate challenges associated with bone cement, providing long-term stability of bone prostheses after implantation. The application of porous titanium and its alloy-based implants is emerging for load-bearing applications due to their high specific strength, low stiffness, corrosion resistance, and superior osteoconductivity. In this study, coagulant-assisted foaming was utilized for the fabrication of porous TiAl V using egg-white foam. Samples with three different porosities of 68.3%, 75.4%, and 83.1% and average pore sizes of 92, 178, and 297 μm, respectively, were prepared and subsequently characterized for mechanical properties, osteogenesis, and tissue ingrowth. A microstructure-mechanical properties relationship study revealed that an increase of porosity from 68.3 to 83.1% increased the average pore size from 92 to 297 μm with the subsequent reduction of compresive strength by 85% and modulus by 90%. Samples with 75.4% porosity and a 178 μm average pore size produced signifcant osteogenic effects on human mesenchymal stem cells, which was further supported by immunocytochemistry and real-time polymerase chain reaction data. Quantitative assessment of bone ingrowth by micro-computed tomography revealed that there was an approximately 52% higher bone formation and more than 90% higher bone penetration at the center of femoral defects in rabbit when implanted with TiAl V foam (75.4% porosity) compared to the empty defects after 12 weeks. Hematoxylin and eosin (H&E) and Masson trichrome (MT) staining along with energy-dispersive X-ray mapping on the sections obtained from the retrieved bone samples support bone ingrowth into the implanted region.
This paper is dedicated to Professor Yoshinori Asakawa for his 65 th birthday. Obesity has reached epidemic proportions globally, with more than 1 billion adults overweight-at least 300 million of them clinically obese. In Ayurveda, obesity is called 'medoroga'. The detailed features and treatments of the disease have been described in an old Ayurvedic text, Charak and Sushrut Samhita. There are some native plants that are commonly used for the treatment of obesity in Ayurveda. Unfortunately, only few medications are available in the market, with side effects and unacceptable efficacy. With the current view that botanical drugs can be developed faster and more cheaply than conventional single entity pharmaceuticals, the review mainly focuses on the rationality of their use with appropriate literature data support.
Post-implantation failure associated with insufficient host tissue integration at the bone–implant interface and aseptic loosening is a major concern in orthopaedics as well as in dentistry.
The
advent of three dimensionally (3D) printed customized bone
grafts using different biomaterials has enabled repairs of complex
bone defects in various in vivo models. However, studies related to
their clinical translations are truly limited. Herein, 3D printed
poly(lactic-
co
-glycolic acid)/β-tricalcium
phosphate (PLGA/TCP) and TCP scaffolds with or without recombinant
bone morphogenetic protein −2 (rhBMP-2) coating were utilized
to repair primate’s large-volume mandibular defects and compared
efficacy of prefabricated tissue-engineered bone (PTEB) over direct
implantation (without prefabrication).
18
F-FDG PET/CT was
explored for real-time monitoring of bone regeneration and vascularization.
After 3-month’s prefabrication, the original 3D-architecture
of the PLGA/TCP-BMP scaffold was found to be completely lost, while
it was properly maintained in TCP-BMP scaffolds. Besides, there was
a remarkable decrease in the PLGA/TCP-BMP scaffold density and increase
in TCP-BMP scaffolds density during ectopic (within latissimus dorsi
muscle) and orthotopic (within mandibular defect) implantation, indicating
regular bone formation with TCP-BMP scaffolds. Notably, PTEB based
on TCP-BMP scaffold was successfully fabricated with pronounced effects
on bone regeneration and vascularization based on radiographic,
18
F-FDG PET/CT, and histological evaluation, suggesting a promising
approach toward clinical translation.
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