Ziyad S. Haidar

Surface functionalization of nanobiomaterials for application in stem cell culture, tissue engineering, and regenerative medicine

Stem cell‐based approaches offer great application potential in tissue engineering and regenerative medicine owing to their ability of sensing the microenvironment and respond accordingly (dynamic behavior). Recently, the combination of nanobiomaterials with stem cells has paved a great way for further exploration. Nanobiomaterials with engineered surfaces could mimic the native microenvironment to which the seeded stem cells could adhere and migrate. Surface functionalized nanobiomaterial‐based scaffolds could then be used to regulate or control the cellular functions to culture stem cells and regenerate damaged tissues or organs. Therefore, controlling the interactions between nanobiomaterials and stem cells is a critical factor. However, surface functionalization or modification techniques has provided an alternative approach for tailoring the nanobiomaterials surface in accordance to the physiological surrounding of a living cells; thereby, enhancing the structural and functional properties of the engineered tissues and organs. Currently, there are a variety of methods and technologies available to modify the surface of biomaterials according to the specific cell or tissue properties to be regenerated. This review highlights the trends in surface modification techniques for nanobiomaterials and the biological relevance in stem cell‐based tissue engineering and regenerative medicine.

Physicochemical characterization of chitosan-hyaluronan-coated solid lipid nanoparticles for the targeted delivery of paclitaxel: a proof-of-concept study in breast cancer cells

AIM To investigate the potential of modified solid lipid nanoparticles (SLN) for the delivery of paclitaxel (PAX). MATERIALS & METHODS SLN loaded with PAX were prepared via modified high-pressure hot homogenization. Formulation parameters were optimized to obtain a high-quality delivery system. SLN cores were coated, layer-by-layer, with a chitosan and hyaluronan (HA) shell. Selectivity toward HA receptors was tested in a breast cancer cell line, MCF-7. RESULTS Stable and reproducible nano-sized and negatively charged nanoparticles resulted. Findings reveal that chitosan-HA-coated SLN facilitated the targeting, cellular uptake and the time-/dose-controlled delivery and release of PAX, enhancing intrinsic chemotherapeutic activities. CONCLUSION SLN are suitable carrier candidates for nano-oncology given their localized, and potent cytotoxic potential overcoming multidrug-resistant cancer cells.

Use of leukocyte and platelet-rich fibrin (L-PRF) in periodontally accelerated osteogenic orthodontics (PAOO): Clinical effects on edema and pain

Background Demand for shorter treatment time is common in orthodontic patients. Periodontally Accelerated Osteogenic Orthodontics (PAOO) is a somewhat new surgical procedure which allows faster tooth movement via combining orthodontic forces with corticotomy and grafting of alveolar bone plates. Leukocyte and Platelet-Rich Fibrin (L-PRF) possess hard- and soft-tissue healing properties. Further, evidence of pain-inhibitory and anti-inflammatory potential is growing. Therefore, this study explores the feasibility, intra- and post-operative effects of using L-PRF in PAOO in terms of post-operative pain, inflammation, infection and post-orthodontic stability. Material and Methods A pilot prospective observational study involving a cohort of 11 patients was carried out. A Wilcko’s modified PAOO technique with L-PRF (incorporated into the graft and as covering membrane) was performed with informed consent. Post-surgical pain, inflammation and infection were recorded for 10 days post-operatively, while the overall orthodontic treatment and post-treatment stability were followed up to 2 years. Results Accelerated wound healing with no signs of infection or adverse reactions was evident. Post-surgical pain was either “mild” (45.5%) or “moderate” (54.5%). Immediate post-surgical inflammation was either “mild” (89.9%) or “moderate” (9.1%). Resolution began on day 4 where most patients experienced either “mild” or no inflammation (72.7% and 9.1%, respectively). Complete resolution was achieved in all patients by day 8. The average orthodontic treatment time was 9.3 months. All cases were deemed stable for 2 years. Conclusions L-PRF is simple and safe to use in PAOO. Combination with traditional bone grafts potentially accelerates wound healing and reduces post-surgical pain, inflammation, infection without interfering with tooth movement and/or post-orthodontic stability, over a 2 years period; thus alleviating the need for analgesics and anti-inflammatory medications. Key words:Periodontally accelerated osteogenic orthodontics, leukocyte and platelet-rich fibrin, corticotomy, osteogenesis, grafts.

3-H in 3-D: Envisaging Beyond the Current Hype, the Hope and Hurdles of Three-Dimensional “Virtual Planning” in Orthognathic Surgery

Recent technical and technological advancements in orthognathic surgery concepts, intricate in the diagnosis and treatment planning for corrections of dento-facial deformities, have achieved stable oro-dental functional occlusion and facial estheti harmony. Undeniably, this can be attributed to the integration of modern, innovative and advanced facial analysis and computeraided imaging exams into well-orchestrated and executed orthodontic and surgical methods. Three-Dimensional (3-D) virtual planning is a fine example. Today, the acquisition of 3-D images of a patient’s craniofacial complex via cone-beam computed tomography (CBCT) , supported by software tools allowing the construction of 3-D dynamic and interactive visual models, eliminates the uncertainty experie ced with two-dimensional images. Thereby allowing for a more accurate or predictable treatment plan and efficient surgery, especial l for patients with complex dento-facial deformities. This review article aims to describe the current benefits as well as shortcomin gs of 3-D virtual planning via discussing examples and illustrations from orthognathic procedures, attained from the reported English and Spanish literature during the last 10 years. It is designed to deliver updated and practical guidelines for dental practitioners and sp cialists (particularly, oral and maxillofacial), as well as researchers involved in 3-D virtual approaches as an alternative to conventi nal/tradi onal surgical planning; thereby validating its superiority or benefits in terms of outcome prediction for soft and hard tissues, ope rational timeand cost-effectiveness; for its integration in day-to-day practise.

Susceptibilidad de Cepas de Candida Oral a Extracto Etanólico del Propóleo Chileno de Olmué

Fungal (or yeast) infections; mycoses, occurring in the oral mucous membranes, of Candida species (mostly C. albicans, a normal component of the oral microbiota), also known as oral thrush or oral candidiasis (OC), can be diagnosed via the recognition of clinical changes and the presence of pseudohyphae, hyphae or yeasts in samples obtained by exfoliative cytology and/or biopsy. Topical pharmacological preparations and drugs such as Nystatin and Miconazole are used in the treatment of CO. However, there are forms of Candida with resistance to such conventional treatment approaches. Therefore, the aim of this study is to determine the in vitro susceptibility of Candida spp.; an ethanolic extract of propolis from Olmué. Hence, an experimental in vitro descriptive study was carried out in which the effect of an ethanolic extract of propolis used as antifungal on strains of Candida spp. obtained from the oral cavity (palatine mucosa) of 31 individuals, diagnosed with OC (subdenture stomatitis) is determined. Natural propolis was obtained from the Olmué area, in the 5th region of Chile. It was found that 100 % of the samples with propolis concentration ranging from 0.1 mg / mL to 1.6 mg / mL presented a degree of inhibition in the growth of OC. On the other hand, the ethanolic extract of propolis that generated inhibition in the largestnumber of samples was 0.4 mg / mL (41.94 % of the samples) followed by the concentration of 0.2 mg / mL (35 % of the samples). Therefore, it can be concluded that the ethanolic extract of Chilean propolis obtained from the Olmué area has the ability to inhibit the growth of Candida spp. in vitro in a dosage-dependent manner.

The Use of the Mandibular Ramus for Alveolar Reconstruction in Oral Implantology

Bone grafts are widely used in alveolar ridge augmentations to allow correct implant installations. Intraoral donor sites, such as the maxillary tuberosity, symphysis and mandibular ramus have presented good characteristics and outcomes; however, the mandibular ramus has comparative advantages that promote its increased use. The aim of this work is to describe the current results of the mandibular ramus as a donor site for obtaining bone grafts to be used in alveolar bone augmentations in oral implantology and to determine the survival rate of the implants installed in the grafted sites. A systematic search of the scientific literature between December 2000 and March 2017 was carried out on the MEDLINE, EMBASE, LILACS and SciELO databases, analyzing each article according to the method of diagnosis and planning, bone resorption at the receptor site, presence of postoperative complications and implant survival rate. Eleven works were included in this study with an average of 43 patients; the follow-up times varied between 6 and 120 months, considering in addition an average success rate of 98.7 % in the implants installed in sites reconstructed with mandibular ramus bone; low morbidity in the site mainly linked to temporary neurosensory alterations was identified. It may be concluded that the need for a second surgical site to obtain graft material and the longer time the treatment requires until implant rehabilitation continue to be disadvantages; nevertheless, the mandibular ramus donor site presents low morbidity, high versatility in its use and predictable results for the dental implant installation.

Inmunoexpresión de E-cadherina y vimentina en mucosa oral normal, displasia epitelial oral y carcinoma oral de células escamosas

RESUMEN: El objetivo fue evaluar la inmunoexpresión de E-cadherina y Vimentina en mucosa oral normal (MON), displasia epitelial oral (DEO) y carcinoma oral de células escamosas (COCE). Se realizó un estudio descriptivo de una serie de casos anal izandolos mediante técnica de inmunohistoquímica contra E-cadherina y Vimentina 16 muestras de MON, 16 de DEO y 19 de COCE. La inmunotinción fue evaluada cualitativamente considerando extensión e intensidad para E-cadherina e intensidad para Vimentina. E l análisis de la extensión e intensidad de la inmunotinción de E-cadherina y Vimentina según diagnóstico reveló una asociación estadísticamente significativa (p<0,001). Siendo la expresión de E-cadherina más alta en MON, seguido por DEO y más baja en COC E, inversamente a lo que se observó con Vimentina. El presente estudio reveló la subregulación del marcador molecular E-cadherina junto con la expresión aberrante por parte de células epiteliales del marcador mesenquimal Vimentina en muestras de MON, DEO y COCE.

Utilidad de Tinción de Tricrómico de Masson en la Cuantificación de Densidad Media Vascular en Mucosa Oral Normal, Displasia Epitelial y Carcinoma Oral de Células Escamosas

RESUMEN: El objetivo de este estudio fue valuar la utilidad del uso de la tinción de Tricrómico de Masson (TM) en la cuantificación de la densidad media vascular (DMV) en Mucosa Oral Normal (MON), Displasia Epitelial Oral (DEO) y Carcinoma Oral de Células Escamosas (COCE). Estudio descriptivo de serie de casos. Se analizaron 17 muestras de MON, 15 muestras de DEO y 16 d e COCE, teñidas con TM. Para determinar su utilidad, se compararon con las mismas muestras analizadas con técnica de inmunohistoq uí ica contra CD31. La cuantificación de la DMV se realizó en las 3 áreas de mayor vascularización de cada muestra. Se determinó la DM V según diagnóstico mediante la tinción TM e inmunohistoquímica contra CD31, y se calculó la correlación entre ambos. La DMV cuantificada con TM y contra CD31 difiere según el diagnóstico, observándose un aumento de la DMV al malignizarse el diagnóstic o. No se encontraron diferencias al comparar la DMV cuantificada con TM y contra CD31. La correlación de la DMV analizado por TM y contra CD31 es significativa y moderada. La cuantificación de vasos sanguíneos es posible mediante la tinción de TM en muestras de MON, DEO y COCE, con una correlación moderada con la inmunohistoquímica contra CD31.

Graftless maxillary sinus lift using lateral window approach: a systematic review

Purpose: The aim was to determine the survival rate of dental implants installed in the posterior region of the maxilla after a graftless maxillary sinus lift via the lateral window approach and to identify the factors involved in the results. Materials and Methods: A systematic search was done on MEDLINE, EMBASE, LILACS, Scopus, and Science Direct up to June 2016; additional studies were identified through an analysis of references. Primary studies in English, Spanish, Portuguese, and French were included; the selection and data extraction process was conducted by 2 investigators independently, and the methodological quality was evaluated by means of the Effective Public Health Practice Projects Quality Assessment Tool. Results: The combined search identified 232 articles. After the selection process, 11 articles were identified, 9 of which were prospective and 2 were retrospective. In all of them, the graftless maxillary sinus lift was done with the immediate installation of the implant. All the studies included presented a low methodological quality. The mean survival rate of the implants was 97% with an average new intrasinus bone formation of 6.2 mm. Conclusion: This technique has a high implant survival although it is not possible to identify its correct indication and contraindication.