Chitosan nanoparticle applications in dentistry: a sustainable biopolymer

The epoch of Nano-biomaterials and their application in the field of medicine and dentistry has been long-lived. The application of nanotechnology is extensively used in diagnosis and treatment aspects of oral diseases. The nanomaterials and its structures are being widely involved in the production of medicines and drugs used for the treatment of oral diseases like periodontitis, oral carcinoma, etc. and helps in maintaining the longevity of oral health. Chitosan is a naturally occurring biopolymer derived from chitin which is seen commonly in arthropods. Chitosan nanoparticles are the latest in the trend of nanoparticles used in dentistry and are becoming the most wanted biopolymer for use toward therapeutic interventions. Literature search has also shown that chitosan nanoparticles have anti-tumor effects. This review highlights the various aspects of chitosan nanoparticles and their implications in dentistry.

Fabrication of 3D Printed poly(lactic acid) strut and wet-electrospun cellulose nano fiber reinforced chitosan-collagen hydrogel composite scaffolds for meniscus tissue engineering

The main goal of the study was to produce chitosan-collagen hydrogel composite scaffolds consisting of 3D printed poly(lactic acid) (PLA) strut and nanofibrous cellulose for meniscus cartilage tissue engineering. For this purpose, first PLA strut containing microchannels was incorporated into cellulose nanofibers and then they were embedded into chitosan-collagen matrix to obtain micro- and nano-sized topographical features for better cellular activities as well as mechanical properties. All the hydrogel composite scaffolds produced by using three different concentrations of genipin (0.1, 0.3, and 0.5%) had an interconnected microporous structure with a swelling ratio of about 400% and water content values between 77 and 83% which is similar to native cartilage extracellular matrix. The compressive strength of all the hydrogel composite scaffolds was found to be similar (∼32 kPa) and suitable for cartilage tissue engineering applications. Besides, the hydrogel composite scaffold comprising 0.3% (w/v) genipin had the highest tan δ value (0.044) at a frequency of 1 Hz which is around the walking frequency of a person. According to the in vitro analysis, this hydrogel composite scaffold did not show any cytotoxic effect on the rabbit mesenchymal stem cells and enabled cells to attach, proliferate and also migrate through the inner area of the scaffold. In conclusion, the produced hydrogel composite scaffold holds great promise for meniscus tissue engineering.

Biofunctional Extracellular Matrix-Polycaprolactone-Hydroxyapatite Scaffold and Synovium Mesenchymal Stem Cells/Chondrocytes for Repairing Cartilage Defects

Articular cartilage defects and degeneration can be caused by multiple factors, and the current clinical treatment schemes for pathological changes are relatively limited. Engineered cartilage tissue represents an alternative therapy for repairing cartilage defects in regenerative medicine. The scaffold material is considered the framework of tissue engineering; thus, scaffold material selection plays a crucial role in the therapy outcome. Polycaprolactone (PCL)-hydroxyapatite (HA) has been applied as a scaffold material for bone and cartilage tissue engineering with nontoxic, harmless metabolites and proper physical properties. The extracellular matrix (ECM) is mainly composed of collagen and proteoglycan, as well as a large number of growth factors and cytokines, which provide a tissue-specific microenvironment for host cells. Adipose-derived stem cells are pluripotent stem cells, and transforming growth factor-β3 (TGF-β3) enables mesenchymal stem cells to promote ECM production. This study, via in vitro and in vivo experiments, elucidated that the synovium mesenchymal stem cells (SMSCs) + chondrocytes + ECM-PCL-HA repair system, which is constructed upon the ECM-PCL-HA scaffold material, exhibits an adequate chondrogenic ability and reparatory effect. Overall, ECM-PCL-HA can be defined as a biofunctional scaffold material. The SMSCs + chondrocytes + ECM-PCL-HA repair system showed good confluency between the new cartilage and the surface, as well as the interface of the adjacent host cartilage. Furthermore, the structure of new cartilage tissue is consistent with adjacency. Thus, it can be used as a preferred plan for articular cartilage defect repair.

From intricate to integrated: Biofabrication of articulating joints

Articulating joints owe their function to the specialized architecture and the complex interplay between multiple tissues including cartilage, bone and synovium. Especially the cartilage component has limited self-healing capacity and damage often leads to the onset of osteoarthritis, eventually resulting in failure of the joint as an organ. Although in its infancy, biofabrication has emerged as a promising technology to reproduce the intricate organization of the joint, thus enabling the introduction of novel surgical treatments, regenerative therapies, and new sets of tools to enhance our understanding of joint physiology and pathology. Herein, we address the current challenges to recapitulate the complexity of articulating joints and how biofabrication could overcome them. The combination of multiple materials, biological cues and cells in a layer-by-layer fashion, can assist in reproducing both the zonal organization of cartilage and the gradual transition from resilient cartilage toward the subchondral bone in biofabricated osteochondral grafts. In this way, optimal integration of engineered constructs with the natural surrounding tissues can be obtained. Mechanical characteristics, including the smoothness and low friction that are hallmarks of the articular surface, can be tuned with multi-head or hybrid printers by controlling the spatial patterning of printed structures. Moreover, biofabrication can use digital medical images as blueprints for printing patient-specific implants. Finally, the current rapid advances in biofabrication hold significant potential for developing joint-on-a-chip models for personalized medicine and drug testing or even for the creation of implants that may be used to treat larger parts of the articulating joint. © 2017 The Authors. Journal of Orthopaedic Research Published by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. J Orthop Res 35:2089-2097, 2017.

Chitosan Biomaterials for Current and Potential Dental Applications

Chitosan (CHS) is a very versatile natural biomaterial that has been explored for a range of bio-dental applications. CHS has numerous favourable properties such as biocompatibility, hydrophilicity, biodegradability, and a broad antibacterial spectrum (covering gram-negative and gram-positive bacteria as well as fungi). In addition, the molecular structure boasts reactive functional groups that provide numerous reaction sites and opportunities for forging electrochemical relationships at the cellular and molecular levels. The unique properties of CHS have attracted materials scientists around the globe to explore it for bio-dental applications. This review aims to highlight and discuss the hype around the development of novel chitosan biomaterials. Utilizing chitosan as a critical additive for the modification and improvement of existing dental materials has also been discussed.

Potential of Electrospun Nanofibers for Biomedical and Dental Applications

Electrospinning is a versatile technique that has gained popularity for various biomedical applications in recent years. Electrospinning is being used for fabricating nanofibers for various biomedical and dental applications such as tooth regeneration, wound healing and prevention of dental caries. Electrospun materials have the benefits of unique properties for instance, high surface area to volume ratio, enhanced cellular interactions, protein absorption to facilitate binding sites for cell receptors. Extensive research has been conducted to explore the potential of electrospun nanofibers for repair and regeneration of various dental and oral tissues including dental pulp, dentin, periodontal tissues, oral mucosa and skeletal tissues. However, there are a few limitations of electrospinning hindering the progress of these materials to practical or clinical applications. In terms of biomaterials aspects, the better understanding of controlled fabrication, properties and functioning of electrospun materials is required to overcome the limitations. More in vivo studies are definitely required to evaluate the biocompatibility of electrospun scaffolds. Furthermore, mechanical properties of such scaffolds should be enhanced so that they resist mechanical stresses during tissue regeneration applications. The objective of this article is to review the current progress of electrospun nanofibers for biomedical and dental applications. In addition, various aspects of electrospun materials in relation to potential dental applications have been discussed.