Effect of hyaluronic acid on bone formation in the expanded interpremaxillary suture in rats

Insights into the source, mechanism and biotechnological applications of hyaluronidases

It has long been found that hyaluronidases exist in a variety of organisms, playing their roles in various biological processes including infection, envenomation and metabolic regulation through degrading hyaluronan. However, exploiting them as a bioresource for specific applications had not been extensively studied until the latest decades. In recent years, new application scenarios have been developed, which extended the field of application, and emphasized the research value of hyaluronidase. This critical review comprehensively summarizes existing studies on hyaluronidase from different source, particularly in their structures, action patterns, and biological functions in human and mammals. Furthermore, we give in-depth insight into the resource mining and protein engineering process of hyaluronidase, as well as strategies for their high-level production, indicating that mixed strategies should be adopted to obtain well-performing hyaluronidase with efficiency. In addition, advances in application of hyaluronidase were summarized and discussed. Finally, prospects for future researches are proposed, highlighting the importance of further investigation into the characteristics of hyaluronidases, and the necessity of investigating their products for the development of their application value.

Rapid maxillary expansion supplementary methods: A scoping review of animal studies

INTRODUCTION

Maxillary constriction is a relatively common condition. Various treatment modalities have been proposed for this condition such as rapid maxillary expansion (RME). Although RME can significantly expand the suture in a relatively short period of time, it has a number of drawbacks, mainly a lengthy retention period. The primary objective of this study was to assess the efficacy of the supplementary methods used in conjunction with RME for new bone formation (NBF) at the midpalatal suture (MPS). Relapse, bone healing, and root resorption were also studied as the secondary outcomes.

MATERIALS AND METHODS

The PubMed, Embase, and Cochrane library online databases were searched according to the PRISMA-ScR guideline. Animal studies on the effects of non-surgical supplementary methods other than laser therapy on NBF in RME were included and reviewed.

RESULT

Thirty-eight articles met the inclusion criteria. The supplementary methods were categorized into 6 groups: hormones, chemical agents, drugs, vitamins, proteins, and some other substances, which could not be assigned to any group. All the aforementioned substances enhanced NBF. Drugs such as bisphosphonates also increased bone resorption. The oestrogen hormone was shown to reduce treatment relapse. Lastly, stem cell application accelerated bone healing at the expanded MPS.

CONCLUSION

Administration of hormones, chemical agents, drugs, vitamins, herbs, and proteins may improve the outcomes of RME, shorten the retention period and consequently, reduce relapse in animals. However, the generalizability of these findings is limited due to the insubstantial number of studies published on each substance.

Do adjunctive interventions in patients undergoing rapid maxillary expansion increase the treatment effectiveness?

OBJECTIVES

To evaluate the clinical effectiveness of adjunctive interventions in individuals undergoing rapid maxillary expansion (RME).

MATERIALS AND METHODS

MEDLINE, Web of Science, Cochrane, Scopus, LILACS, and Google Scholar were searched without restrictions up to June 2020. Trials involving participants undergoing orthopedic or surgical RME, along with adjunctive interventions, were included. Risk-of-bias assessments were performed using the Cochrane tool for randomized trials-2. The certainty level of evidence was assessed through the Grading of Recommendations Assessment, Development and Evaluation tool.

RESULTS

Six randomized clinical trials, with low to high risk of bias, were included. Low certainty of the evidence suggested that low-level laser facilitated opening of the midpalatal suture during the active phase of RME. Likewise, moderate certainty demonstrated that low-level laser accelerated the healing process of the suture during the retention phase. The clinical impact of this outcome, that is, stability and retention time, was not evaluated. Very low evidence indicated that osteoperforations along the midpalatal suture increased maxillary transverse skeletal gains in young adults undergoing RME. Low evidence suggested that platelet-rich plasma therapy did not minimize the vertical and thickness bone loss after RME in the short term.

CONCLUSIONS

Based on currently available information, the use of low-level laser associated with maxillary expansion seems to provide a more efficient suture opening and bone healing. Limited evidence suggests that osteoperforations improve the skeletal effects of RME in non-growing individuals. There are no adjunctive interventions capable of reducing the periodontal side effects of RME.

Relaxin 2 carried by magnetically directed liposomes accelerates rat midpalatal suture expansion and subsequent new bone formation

Relaxin (RLN) is an insulin-like peptide hormone that enables softening and lengthening of the pubic symphysis and uterine cervix. Here, we analyzed the effects of RLN2 on the expansion of rat midpalatal suture (MPS) using a magnetically directed liposome-based drug delivery system. Thirty-six male rats were divided into three groups: control (MPS was not expanded), lipo (expanded for 1 week with vehicle liposomes encapsulating ferric oxide and Cy5.5), and RLN-lipo (expanded for 1 week with the liposomes coated with RLN2). Rats were sacrificed after 1 week of expansion or after 2 weeks of retention. To accumulate RLN2-liposomes, a magnetic sheet was fixed to the palatal mucosa of the MPS. In vivo imaging showed magnetically controlled accumulation of liposomes in the MPS for 72 h. Immunohistochemistry revealed RLN2 expression in the MPS after expansion and relaxin receptor (RXFP) 2 expression at the osteogenic front (OF) in the RLN-lipo group; all groups expressed RXFP1 in the MPS. MPS expansion and bone formation were significantly accelerated at the OF in RLN-lipo group compared with the other groups. In the RLN-lipo group, significantly accelerated serrate bone deposition and elevated periostin (POSTN), iNOS, and MMP-1 levels were observed in the MPS. Sclerostin (SOST) expression was significantly reduced in newly formed bone in the RLN-lipo group. Our data revealed that RLN2 enhanced suture expansion via MMP-1 and iNOS secretion in the sutural fibroblasts and new bone formation via POSTN expression in osteoblasts at the OF. These properties may be useful for developing a new less-invasive orthopedic treatment aiming at sutural modification of cranio- and maxillofacial deformity patients.

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In vivo Magnetically localization of RLN2 carried by liposome at rat midpalatal suture (MPS) was originally performed.

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RLN2 promoted efficiency of the MPS expansion with secretion of Mmp1 and iNos in the mid-sutural fibroblasts.

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During expansion period, RLN2 increased the number and differentiation of osteoblast cells in the MPS.

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RLN2 enhanced newly bone formation at the MPS during expansion and retention period through Rxfp2.

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Sinus-like bone formation and Postn localization at the expanded MPS was observed by RLN2 administration.

Effects of curcumin and melatonin on bone formation in orthopedically expanded suture in rats: A biochemical, histological and immunohistochemical study

OBJECTS

To investigate the effects of curcumin (CUR) and melatonin (MEL) on new bone formation following rapid maxillary expansion (RME) in rats.

SETTING AND SAMPLE POPULATION

For this study, 24 12-week-old adult male Wistar albino rats from the Animal Laboratory at Adnan Menderes University, Faculty of Medicine, were used.

MATERIALS AND METHODS

The rats were randomly divided into the following 3 groups (n = 8 each): only expansion (OE), expansion plus MEL (MEL) and expansion plus CUR (CUR). CUR and MEL were given to the rats during the study period. After the sacrifice of the animals, biochemical, histological and immunohistochemical examinations were performed.

RESULTS

Serum bone alkaline phosphatase levels in the MEL group were statistically (P = .007) higher than in the OE group. Serum glutathione peroxidase and catalase activities in the CUR and MEL groups were significantly higher than in the OE group (P = .007 and P = .021, respectively). Inflammatory cell infiltration, new bone formation and capillary intensity parameters did not demonstrate statistically significant differences between the groups (P = .865, P = .067 and P = .055, respectively). The immunohistochemical findings revealed that IL-1, IL-6 and TNF-α H scores showed considerable differences between the groups (all P < .001). The highest IL-1, IL-6 and TNF-α H scores were found in the OE groups rather than in the other groups (P < .001).

CONCLUSION

CUR and MEL treatments may be effective in accelerating new bone formation and beneficial in preventing relapse following the RME procedures.