Mina D. Fahmy

Dental Applications of Natural-Origin Polymers in Hard and Soft Tissue Engineering.

Clinical advances in the treatment of dentoalveolar defects continue to evolve with the introduction of new innovations in regenerative medicine and tissue bioengineering. Recent developments in tissue engineering are aimed at safely and effectively regenerating a damaged or necrotic area by replenishing its cells and increasing surrounding gene expression. Various techniques have successfully given rise to porous scaffolds being used by clinicians to treat the defect and initiate the repair process. Tissue reconstruction using bioengineered scaffolds is advantageous over traditional autografting, since it prevents the instigation of pain and donor site morbidity while ultimately creating both the environment and machinery needed to induce cell proliferation, migration, and reattachment within the affected area. This review article aims to describe and review the available literature regarding the regenerative capacity of natural polymers used for the treatment of dentoalveolar defects. The repair mechanisms, advantages of protein and polysaccharide derivatives, and the potential of stem cell therapy are discussed.

Green Chemical and Biological Synthesis of Nanoparticles and Their Biomedical Applications

To generate nanoparticles with particular shapes and dimensions, various techniques including physicochemical and biological routes have been developed. The physical and chemical processes are typically expensive and require hazardous chemicals. In this chapter, we introduce current advancements in the green synthesis of nanoparticles as eco-friendly, cost-effective, and simple approaches. The microbial synthesis of nanoparticles using bacteria, fungi, and viruses; phototrophic eukaryotes including plants, diatoms, and algae; heterotrophic human cell lines and some other biological agents is especially emphasized in this review. It also declares the applications of these nanomaterials in a broad range of potential areas, such as medical biology, labeling, sensors, drug delivery, dentistry, and environmental cleanup.

Nanobiomaterials in periodontal tissue engineering

Periodontitis is an inflammatory disease of the gums which spreads and affects the supporting tooth structures possibly leading to the loosening and loss of the tooth. Periodontal tissue engineering is considered a relatively new technique for the stimulation of the periodontal tissue formation using the basics of regenerative medicine. In this method, biodegradable porous scaffolds are employed as a temporary substitution of the injured or lost tissues to facilitate the regeneration process. Scaffolds are usually made of natural or synthetic polymers and ceramics doped with various nanobiomaterials for an intended functionalization. The addition of nanoparticles into the scaffold structure not only enhances the biomineralization potential of the composite scaffolds, but also improves their mechanical properties. Nanosized ceramic particles are of special importance as they mimic the mineral crystal structure of the natural tissues. They have been demonstrated to induce a considerable enhancement in the protein absorption and the cell adhesion compared to their micro-sized counterparts. This chapter reviews different nanobiomaterials employed in periodontal tissue engineering for the effective regeneration of lost tissues and discuss their benefits and drawbacks.

CHAPTER 8:Smart Biomaterials for Tissue Engineering of Cartilage

Smart materials have made significant changes within the realm of tissue engineering research. Smart biomaterials have the unique ability to respond to their environments, and interact with different biological systems in turn producing specific responses. In this chapter, we focus on the tissue engineering of cartilage with the use of smart materials. Specifically, we will discuss the desired properties of such materials for optimal biological responses and why certain natural and synthetic materials are used. We also examine the use of smart matrices in the context of those that are thermo-responsive, pH-responsive, bioactive agent releasing, and self-assembling matrices. Response to dynamic loading, as well as the use of matrix metalloproteinase and shape-memory systems are explored. Finally, future applications of smart materials within a broad scope are considered.

Salivary MMP-9 in the Detection of Oral Squamous Cell Carcinoma

Background Oral squamous cell carcinoma (OSCC) is the most common malignant tumour of the oral cavity. Detection of OSCC is currently based on clinical oral examination combined with histopathological evaluation of a biopsy sample. Direct contact between saliva and the oral cancer makes measurement of salivary metalloproteinase- 9 (MMP-9) an attractive alternative. Material and Methods In total, 30 OSCC patients and 30 healthy controls were included in this prospective study. Saliva samples from both groups were collected, centrifuged and supernatant fluid was subjected to ELISA for assessment of MMP-9. The median salivary MMP-9 values with interquartile range (IQR) of OSCC patients and the control group were statistically analysed using the Mann-Whitney U-test. The receiver operating characteristic (ROC) curve was constructed and the area under curve (AUC) was computed. Results The median absorbance MMP-9 value of the OSCC group was 0.186 (IQR=0.158) and that of control group was 0.156 (IQR=0.102). MMP-9 was significantly increased in the OSCC patients than in the controls by +19.2% (p=0.008). Median values in patients with recurrence and in patients with primary event were 0.233 (IQR=0.299) and 0.186 (IQR=0.134) respectively. MMP-9 was significantly increased in patients with primary event (p=0.017) compared to controls by +19.2%. No significant increase of MMP-9 level was detected when comparing patients with recurrence and healthy controls (+49.4%; p=0.074). The sensitivity value of MMP-9 was 100% whereas the specificity value was 26.7% with AUC of 0.698. Conclusions The present data indicates that the elevation of salivary levels of MMP-9 may be a useful adjunctive diagnostic tool for detection of OSCC. However, further studies are necessary to provide scientific and clinical validation. Key words:Oral squamous cell carcinoma, oral cancer, saliva, salivary diagnostics, cancer detection, MMP-9, metalloproteinases.

Craniofacial surgery, orthodontics, and tissue engineering

Abstract Although bone grafting has been the gold standard for several decades, tissue engineering has been gaining momentum in the fields of craniofacial surgery and orthodontics. In this chapter we highlight the use of state of the art methods and materials, including the use of scaffolds and their ideal properties, as well as the incorporation of stem cells for regeneration of craniofacial structures. Furthermore, we explore the causes of alveolar bone defects, and different methods of repair including the use of guided bone regeneration, use of growth factors and gene therapy. Periodontal ligament tissue engineering is examined throughout this chapter within the scope of orthodontics and dentofacial orthopedics. Finally, we shed light on a relatively novel method that has been discussed in literature known as low-intensity pulsed ultrasound (LIPUS). This approach provides mechanical stimulation to tissues and enhances new blood vessel formation, which is important for the process of integrating newly formed tissues. LIPUS has been shown to reduce root resorption throughout clinical orthodontic treatment as well as increase the efficiency of tooth movement. Limitations along with significant future applications within the realm of craniofacial treatment are discussed.

Treatment of a Periodontic-Endodontic Lesion in a Patient with Aggressive Periodontitis.

Case Description. This case report describes the successful management of a left mandibular first molar with a combined periodontic-endodontic lesion in a 35-year-old Caucasian woman with aggressive periodontitis using a concerted approach including endodontic treatment, periodontal therapy, and a periodontal regenerative procedure using an enamel matrix derivate. In spite of anticipated poor prognosis, the tooth lesion healed. This case report also discusses the rationale behind different treatment interventions. Practical Implication. Periodontic-endodontic lesions can be successfully treated if dental professionals follow a concerted treatment protocol that integrates endodontic and periodontic specialties. General dentists can be the gatekeepers in managing these cases.