Randa Alfotawi | King Saud University (original) (raw)

Papers by Randa Alfotawi

Bioengineering, 2019

Graphene is an excellent filler for the development of reinforced composites. This study evaluate... more Graphene is an excellent filler for the development of reinforced composites. This study evaluated bone cement composites of graphene oxide (GO) and poly(methyl methacrylate) (PMMA) based on the proliferation of human bone marrow mesenchymal stem cells (hBMSCs), and the anabolic and catabolic effects of the incorporation of GO on osteoblast cells at a genetic level. Surface wettability and roughness were also evaluated at different GO concentrations (GO1: 0.024 wt% and GO2: 0.048 wt%) in the polymer matrix. Fabricated specimens were tested to (a) observe cell proliferation and (b) identify the effectiveness of GO on the expression of bone morphogenic proteins. Early osteogenesis was observed based on the activity of alkaline phosphatase and the genetic expression of the run-related transcription factor 2. Moreover, bone strengthening was determined by examining the collagen type 1 alpha-1 gene. The surface roughness of the substrate material increased following the addition of GO fillers to the resin matrix. It was found that over a period of ten days, the proliferation of hBMSCs on GO2 was significantly higher compared to the control and GO1. Additionally, quantitative colorimetric mineralization of the extracellular matrix revealed greater calcium phosphate deposition by osteoblasts in GO2. Furthermore, alizarin red staining analysis at day 14 identified the presence of mineralization in the form of dark pigmentation in the central region of GO2. The modified GO-PMMA composite seems to be promising as a bone cement type for the enhancement of the biological activity of bone tissue.

Resin composite bone implants have recently been developed. Their foundation is relying on thermo... more Resin composite bone implants have recently been developed. Their foundation is relying on thermoplastic or thermoset resin systems with high-aspect-ratio fillers and bioactive compounds. This research sets out to evaluate some physical and biological properties of thermoplastic poly(methyl methacrylate) (PMMA) composites reinforced with single-walled carbon nanotubes (SWCNTs) or multi-walled carbon nanotubes (MWCNTs) as an implant material. PMMA specimens were fabricated via heat curing method for optimizing biocompatibility of the polymer phase. In control group (C), PMMA was used as such, whereas in remaining two groups either single-walled CNTs (SW) or multi-walled CNTs (MW) were added at 0.5 wt% to the resin monomer system. Physical properties were quantitatively evaluated using non-contact surface profilometer, atomic force microscope (AFM) and surface tensiomter. While the biological properties were investigated using cell viability and differentiation potential of hTERT-MSC-CL1 cells. The surface roughness and hydrophobicity of SW were statistically higher (ANOVA, p ≤ 0.05) compared to the control (C). The incorporation of CNTs, irrespective of their type, demonstrated an insignificant effect on the cultured MSCs, compared to the control. All specimens demonstrated favourable osteoblast differentiation potential when observed under Alizarin redS staining. The addition of single and multi-walled CNTs in PMMA resin matrix may have beneficial surface characteristics. The CNTs incorporated bone implants may allow growth and adherence of new bone tissue around the implant.

The challenge of treating large osseous defects presents a formidable problem for orthopedic and ... more The challenge of treating large osseous defects presents a formidable problem for orthopedic and maxillofacial surgeons. The present method of choice to replace lost tissue is autologous bone grafting, but supplies of autologous bone are limited and harvesting of the graft is associated with donor site morbidities [1]. Artificial biomaterials offer much promise, but do not, by themselves, supply the osteo-progenitor cells needed for bone formation. Moreover, there are often issues with resorption of the scaffold used in the biomaterial, coupled with inadequate vascularization. To address this short- fall, the use of a muscle flap that can act as a bio-reactor for the growth of mesenchymal stromal cells, which can then provide a composite bone mineral for maxillofacial reconstruction has been reported [2]. The role of muscle in bone regeneration has not been studied extensively, however there is proof that muscle has the propensity to induce bone formation because of its intrinsic osteogenic potential when exposed to osteogenic stimuli including bone matrix substitutes and bone morphogenic proteins [3-5]. The most accepted mechanism behind bone formation is that an inflammatory response at the surgical site, and the presence of oestrogenic stimuli amplify the signalling of exogenous BMP-7, triggers the MAPK pathway, as explained by Hassel et al. [6].

Introduction: There is compelling evidence that prophylactic extraction of third molars is a heal... more Introduction: There is compelling evidence that prophylactic extraction of third molars is a health problem that needs to be addressed. In particular, the vast amount of evidence demonstrating complications after removal of third molars, rather than supporting the necessity of removal or the negative effects of retention, raise this concern. Objective: The aim of this study was to investigate the referral system for third molar extraction at our institution by assessing patient opinions and the experience of the oral surgeons and the referring dentists. The main outcome measures of concern were the reasons for third molar extraction, patient awareness about the surgery and the comorbidities that may accompany the surgery. Methods: Pilot cross-sectional survey questionnaires were distributed at the Dental Faculty Clinic at King Saud University, from 15 March 2015 to 30 June 2016 by the staff in charge of the patient waiting area, oral surgery clinic, primary care clinic and specialist clinic. Results: Of 400 potential respondents, 226 completed the survey (response rate: 54%). Of these patients, 91% knew why they had been referred to the oral surgery department, but 73.5% did not understand the surgical extraction procedure or its complications. In total, 45.2% of the patients referred had no signs or symptoms, and 36% were referred for prophylactic reasons. In conclusion, our system needs reassessment. To combat the subjective health practice of routinely referring patients for prophylactic extraction, the role of primary care should be emphasised by implementing a system for regular patient checkups , and public awareness should be increased.

The use of TriCalcium Phosphate (TCP) and stem cells for the regeneration of osteoperiosteal critical-size mandibular bony defects, an in vitro and preclinical study

Journal of Cranio-Maxillofacial Surgery, 2014

The investigation aims to assess the reconstruction of critical-size mandibular bone defects in r... more The investigation aims to assess the reconstruction of critical-size mandibular bone defects in rabbits using beta-Tricalcium Phosphate (β-TCP) scaffolding loaded with stem cells. A 20 mm-long mandibular osteoperiosteal continuity defect was created in 8 New Zealand rabbits and filled with β-TCP scaffolding. In 6 cases bone marrow stem cells (BMSCs) harvested, and enriched, from the posterior iliac crest of the same rabbit were seeded into the scaffolding, while a scaffold was used alone in two cases chosen at random. Radiographic analysis was carried out immediately following surgery and 4, 8 and 12 weeks postoperatively. Cone Beam CT (CBCT) scanning, biomechanical testing and histology assessments were carried out on the explanted mandibles three months postoperatively. The radiography showed minimal new bone formation in all the cases, with significant amounts of undegraded scaffold material visible. Sporadic areas of bone formation were seen, these did not bridge the gap of the created surgical defect. The mechanical properties of the regenerated bone were of an inferior quality when compared with that of the contralateral non-operated side. The addition of BMSCs to the biodegradable β-TCP scaffold did not improve reconstruction of the created mandibular defect. Despite successful aspiration and culture of BMSCs, the survival of these cells in vivo was questionable.

The useof an induced muscle flap to reconstruct mandibular defects

A Novel Surgical Approach for the Reconstruction of Critical-Size Mandibular Defects Using Calcium Sulphate/Hydroxyapatite Cement, BMP-7 and Mesenchymal Stem Cells-Histological Assessment

Journal of Biomaterials and Tissue Engineering, 2016

Reconstruction of maxillofacial continuity defects has always been a challenging tasks for the sc... more Reconstruction of maxillofacial continuity defects has always been a challenging tasks for the scientist and surgeons over the years. The main goal of the reconstruction of the maxillofacial region is to restore facial form, function, full rehabilitation of occlusion and articulation. A refinement in surgical technique and methods of reconstruction has improved patient’s quality of life. This manuscript reviewed exciting methods of bone reconstruction and confirms that the ideal system for reconstruction of critical size continuity defect of the jaw bones has yet to be found. Shortcoming and limitation of each method has been discussed. The author highlight recent advances on how tissue engineering which could offer biological substitute to restore, maintain, or improve oro-facial function.

Biomaterial in the reconstruction of the oral and maxillofacial region

Reconstruction of maxillofacial bones has proven to be complex due to the aesthetic requirements ... more Reconstruction of maxillofacial bones has proven to be complex due to the aesthetic requirements and functional demands of the jaw. Although autogenous bone grafts and a wide range of biomaterials are routinely used for facial bone reconstruction, these methods are associated with a number of drawbacks, including the limited availability of autogenous grafts and the morbidity associated with bone graft harvesting, whilst biomaterials are also linked with a high failure rate. These limitations have inspired the search for innovative techniques for bone bioengineering and the development of more reliable biomaterials. Tissue engineering approaches yield powerful tools for long-term satisfying results enabling customized reconstruction and the support of natural healing processes. There is no doubt that further advances in tissue engineering are essential to achieve reliable and satisfactory clinical outcomes for patients. This chapter will highlight the clinical application of biomaterials and provide an overview of the current scientific concepts in the field.

PLoS ONE, 2014

This study presents a comprehensive radiographic evaluation of bone regeneration within a pedicle... more This study presents a comprehensive radiographic evaluation of bone regeneration within a pedicled muscle flap for the reconstruction of critical size mandibular defect. The surgical defect (20 mm615 mm) was created in the mandible of ten experimental rabbits. The masseter muscle was adapted to fill the surgical defect, a combination of calcium sulphate/ hydroxyapatite cement (CERAMENT TM |SPINE SUPPORT), BMP-7 and rabbit mesenchymal stromal cells (rMSCs) was injected inside the muscle tissue. Radiographic assessment was carried out on the day of surgery and at 4, 8, and 12 weeks postoperatively. At 12 weeks, the animals were sacrificed and cone beam computerized tomography (CBCT) scanning and micro-computed tomography (m-CT) were carried out. Clinically, a clear layer of bone tissue was identified closely adherent to the border of the surgical defect. Sporadic radio-opaque areas within the surgical defect were detected radiographically. In comparison with the opposite non operated control side, the estimated quantitative scoring of the radio-opacity was 46.6% 615, the mean volume of the radio-opaque areas was 63.4% 620. Areas of a bone density higher than that of the mandibular bone (+35% 625%) were detected at the borders of the surgical defect. The micro-CT analysis revealed thinner trabeculae of the regenerated bone with a more condensed trabecular pattern than the surrounding native bone. These findings suggest a rapid deposition rate of the mineralised tissue and an active remodelling process of the newly regenerated bone within the muscle flap. The novel surgical model of this study has potential clinical application; the assessment of bone regeneration using the presented radiolographic protocol is descriptive and comprehensive. The findings of this research confirm the remarkable potential of local muscle flaps as local bioreactors to induce bone formation for reconstruction of maxillofacial bony defects.

Cements for maxillofacial reconstruction of jaw defects through calcification of rotated muscle h... more Cements for maxillofacial reconstruction of jaw defects through calcification of rotated muscle have been tested. The objective of this study was to investigate the visibility of loading of two types of commercially available cements, Cerament ™ Spine Support and Cerament Bone Void Filler with mesenchymal cells and cytokines (bone morphogenetic protein) to act as a biomimetic scaffolding for future clinical application. Determination of basic biocompatibility (cell viability) using methyl thiazolyl tetrazolium and live/dead assay was carried out using MG-63 cells at various time points. Next, in order to inform potential subsequent in vivo experiments, a collagen tissue mimic was used for characterization of rabbit mesenchymal stromal cells using immunofluorescent cytoskeleton staining, and simultaneous and then sequential injection of Cerament Spine Support cement and cells into collagen gels. Results indicated that Cerament Spine Support was more biocompatible and that sequential injection of cement and then rabbit mesenchymal stromal cells into the tissue mimics is an optimal approach for clinical applications.

Reconstruction of maxillofacial continuity defects has always been a challenging tasks for the sc... more Reconstruction of maxillofacial continuity defects has always been a challenging tasks for the scientist and surgeons over the yeas. The main goal of the reconstruction of the maxillofacial region is to restore facial form, function, full rehabilitation of occlusion and articulation. A refinement in surgical technique and methods of reconstruction has improved patient's quality of life. This manuscript reviewed exciting methods of bone reconstruction and confirms that the ideal system for reconstruction of critical size continuity defect of the jaw bones has yet to be found. Shortcoming and limitation of each method has been discussed. The author highlight recent advance in on how tissue engineering which could offer biological substitute to restore, maintain, or improve oro-facial function.

Bioengineering, 2019

The use of TriCalcium Phosphate (TCP) and stem cells for the regeneration of osteoperiosteal critical-size mandibular bony defects, an in vitro and preclinical study

Journal of Cranio-Maxillofacial Surgery, 2014

The useof an induced muscle flap to reconstruct mandibular defects

A Novel Surgical Approach for the Reconstruction of Critical-Size Mandibular Defects Using Calcium Sulphate/Hydroxyapatite Cement, BMP-7 and Mesenchymal Stem Cells-Histological Assessment

Journal of Biomaterials and Tissue Engineering, 2016

Biomaterial in the reconstruction of the oral and maxillofacial region

PLoS ONE, 2014

Reconstruction of maxillofacial continuity defects has always been a challenging tasks for the sc... more Reconstruction of maxillofacial continuity defects has always been a challenging tasks for the scientist and surgeons over the yeas. The main goal of the reconstruction of the maxillofacial region is to restore facial form, function, full rehabilitation of occlusion and articulation. A refinement in surgical technique and methods of reconstruction has improved patient's quality of life. This manuscript reviewed exciting methods of bone reconstruction and confirms that the ideal system for reconstruction of critical size continuity defect of the jaw bones has yet to be found. Shortcoming and limitation of each method has been discussed. The author highlight recent advance in on how tissue engineering which could offer biological substitute to restore, maintain, or improve oro-facial function.