Applying nano-HA in addition to scaling and root planing increases clinical attachment gain.

PURPOSE: This study evaluated the efficacy of treating periodontitis using subgingival nano-hydroxyapatite powder with an air abrasion device (NHAPA) combined with scaling and root planing (SRP). METHODS: A total of 28 patients with stage III periodontitis (grade B) were included in this study, although 1 was lost during follow-up and 3 used antibiotics. The patients were divided into a test group and a control group. All patients first received whole-mouth SRP using hand instruments, and a split-mouth approach was used for the second treatment. In the test group, the teeth were treated with NHAPA for 15 seconds at 70% power per pocket. Subgingival plaque samples were obtained from the 2 deepest pockets at the test and control sites before treatment (baseline) and 3 months after treatment. The full-mouth plaque index (PI), gingival index (GI), papillary bleeding index (PBI), bleeding on probing (BOP), probing depth (PD) and clinical attachment level (CAL) were recorded at baseline and at 1- and 3-month post-treatment. Real-time polymerase chain reaction was used to determine the colonisation of Treponema denticola (Td), Porphyromonas gingivalis (Pg), and Aggregatibacter actinomycetemcomitans in the subgingival plaque. RESULTS: From baseline to the first month, the test group showed significantly larger changes in BOP and CAL (43.705%±27.495% and 1.160±0.747 mm, respectively) than the control group (36.311%±27.599% and 0.947±0.635 mm, respectively). Periodontal parameters had improved in both groups at 3 months. The reductions of PI, GI, BOP, PD, and CAL in the test group at 3 months were greater and statistically significant. The total bacterial count and Td and Pg species had decreased significantly by the third month in both groups (P<0.05). CONCLUSIONS: Applying NHAPA in addition to SRP improves clinical periodontal parameters more than SRP alone. Subgingival NHAPA may encourage clot adhesion to tooth surfaces by increasing surface wettability.

Evaluation of periodontal health in breast cancer patients undergoing tamoxifen or aromatase inhibitors drugs therapy: A cross-sectional study.

AIM: To study the dental and periodontal status of women with breast cancer (BCa) having tamoxifen or aromatase inhibitors (AIs) treatment in comparison with control healthy women. METHODS: Fifty-one women on tamoxifen therapy, 52 women on AIs therapy and 52 systemically healthy controls were included in the study. The total number of teeth, the number of teeth indicated for extraction, the number of decayed teeth, and the duration of medication were recorded. Periodontal status was evaluated with gingival index (GI); plaque index (PI); bleeding on probing (BOP); probing depth (PD) and clinical attachment loss (CAL). RESULTS: The lowest number of teeth and decayed teeth was found in AIs users (P < .001 and P = .003 respectively). The highest CAL value was seen in AIs users (P = .042) whereas no significant difference was found between the groups in terms of PI, GI, and PD (P = .102, P = .233, and P = .306, respectively). Lower PI was observed in patients using AIs for less than 2 years (P = .048). CONCLUSIONS: While tamoxifen did not affect the dental and periodontal condition, AIs medication adversely affected the dental and periodontal condition by more tooth loss and higher CAL.

Collagen Peptide Presenting Nanofibrous Scaffold for Intervertebral Disc Regeneration.

Lower back pain (LBP) is a prevalent spinal symptom at the lumbar region of the spine, which severely effects quality of life and constitutes the number one cause of occupational disability. Degeneration of the intervertebral disc (IVD) is one of the well-known causes contributing to the LBP. Therapeutic biomaterials inducing IVD regeneration are promising candidates for IVD degeneration treatments. Here, we demonstrate a collagen peptide presenting nanofiber scaffold to mimic the structure and function of the natural extracellular matrix of the tissue for IVD regeneration. The collagen peptide presenting nanofiber was designed by using a Pro-Hyp-Gly (POG) peptide sequence on a self-assembling peptide amphiphile molecule, which assembled into nanofibers forming scaffolds. Injection of collagen peptide presenting peptide nanofiber scaffold into the degenerated rabbit IVDs induced more glycosaminoglycan and collagen deposition compared to controls. Functional recovery of the tissue was evaluated by degeneration index score, where the bioactive scaffold was shown to provide functional recovery of the IVD degeneration. These results showed that the collagen peptide presenting nanofiber scaffold can prevent the progression of IVD degeneration and provide further functional recovery of the tissue.

Supramolecular Peptide Nanofiber Morphology Affects Mechanotransduction of Stem Cells.

Chirality and morphology are essential factors for protein function and interactions with other biomacromolecules. Extracellular matrix (ECM) proteins are also similar to other proteins in this sense; however, the complexity of the natural ECM makes it difficult to study these factors at the cellular level. The synthetic peptide nanomaterials harbor great promise in mimicking specific ECM molecules as model systems. In this work, we demonstrate that mechanosensory responses of stem cells are directly regulated by the chirality and morphology of ECM-mimetic peptide nanofibers with strictly controlled characteristics. Structural signals presented on l-amino acid containing cylindrical nanofibers (l-VV) favored the formation of integrin ß1-based focal adhesion complexes, which increased the osteogenic potential of stem cells through the activation of nuclear YAP. On the other hand, twisted ribbon-like nanofibers (l-FF and d-FF) guided the cells into round shapes and decreased the formation of focal adhesion complexes, which resulted in the confinement of YAP proteins in the cytosol and a corresponding decrease in osteogenic potential. Interestingly, the d-form of twisted-ribbon like nanofibers (d-FF) increased the chondrogenic potential of stem cells more than their l-form (l-FF). Our results provide new insights into the importance and relevance of morphology and chirality of nanomaterials in their interactions with cells and reveal that precise control over the chemical and physical properties of nanostructures can affect stem cell fate even without the incorporation of specific epitopes.

Laminin mimetic peptide nanofibers regenerate acute muscle defect.

Skeletal muscle cells are terminally differentiated and require the activation of muscle progenitor (satellite) cells for their regeneration. There is a clinical need for faster and more efficient treatment methods for acute muscle injuries, and the stimulation of satellite cell proliferation is promising in this context. In this study, we designed and synthesized a laminin-mimetic bioactive peptide (LM/E-PA) system that is capable of accelerating satellite cell activation by emulating the structure and function of laminin, a major protein of the basal membrane of the skeletal muscle. The LM/E-PA nanofibers enhance myogenic differentiation in vitro and the clinical relevance of the laminin-mimetic bioactive scaffold system was demonstrated further by assessing its effect on the regeneration of acute muscle injury in a rat model. Laminin mimetic peptide nanofibers significantly promoted satellite cell activation in skeletal muscle and accelerated myofibrillar regeneration following acute muscle injury. In addition, the LM/E-PA scaffold treatment significantly reduced the time required for the structural and functional repair of skeletal muscle. This study represents one of the first examples of molecular- and tissue-level regeneration of skeletal muscle facilitated by bioactive peptide nanofibers following acute muscle injury. SIGNIFICANCE STATEMENT: Sports, heavy lifting and other strength-intensive tasks are ubiquitous in modern life and likely to cause acute skeletal muscle injury. Speeding up regeneration of skeletal muscle injuries would not only shorten the duration of recovery for the patient, but also support the general health and functionality of the repaired muscle tissue. In this work, we designed and synthesized a laminin-mimetic nanosystem to enhance muscle regeneration. We tested its activity in a rat tibialis anterior muscle by injecting the bioactive nanosystem. The evaluation of the regeneration and differentiation capacity of skeletal muscle suggested that the laminin-mimetic nanosystem enhances skeletal muscle regeneration and provides a suitable platform that is highly promising for the regeneration of acute muscle injuries. This work demonstrates for the first time that laminin-mimetic self-assembled peptide nanosystems facilitate myogenic differentiation in vivo without the need for additional treatment.

Presentation of functional groups on self-assembled supramolecular peptide nanofibers mimicking glycosaminoglycans for directed mesenchymal stem cell differentiation.

Organizational complexity and functional diversity of the extracellular matrix regulate cellular behaviors. The extracellular matrix is composed of various proteins in the form of proteoglycans, glycoproteins, and nanofibers whose types and combinations change depending on the tissue type. Proteoglycans, which are proteins that are covalently attached to glycosaminoglycans, contribute to the complexity of the microenvironment of the cells. The sulfation degree of the glycosaminoglycans is an important and distinct feature at specific developmental stages and tissue types. Peptide amphiphile nanofibers can mimic natural glycosaminoglycans and/or proteoglycans, and they form a synthetic nanofibrous microenvironment where cells can proliferate and differentiate towards different lineages. In this study, peptide nanofibers were used to provide varying degrees of sulfonation mimicking the natural glycosaminoglycans by forming a microenvironment for the survival and differentiation of stem cells. The effects of glucose, carboxylate, and sulfonate groups on the peptide nanofibers were investigated by considering the changes in the differentiation profiles of rat mesenchymal stem cells in the absence of any specific differentiation inducers in the culture medium. The results showed that a higher sulfonate-to-glucose ratio is associated with adipogenic differentiation and a higher carboxylate-to-glucose ratio is associated with osteochondrogenic differentiation of the rat mesenchymal stem cells. Overall, these results demonstrate that supramolecular peptide nanosystems can be used to understand the fine-tunings of the extracellular matrix such as sulfation profile on specific cell types.