Low-Intensity Ultrasound Combined with Hematoporphyrin Monomethyl Ether in the Treatment of Experimental Periodontitis in Rats

Effect of SDT on Ligature-Induced Periodontitis in Rats With and Without Diabetes

OBJECTIVE

This study aimed to evaluate the effect of hematoporphyrin monomethyl ether (HMME)-mediated sonodynamic therapy (SDT) on experimental periodontal disease in rats with diabetes.

METHODS

72 rats were randomly divided into two groups: non-diabetic (ND; n = 36) and diabetic (D; n = 36). Diabetes was induced by an intraperitoneal injection of streptozotocin (STZ). Periodontal disease was induced in both groups at the maxillary second molars for 4 weeks. Then the rats received the following treatments: sterile saline solution (control group); scaling and root planing (SRP group); HMME (40 μg/mL) plus 3 W/cm2 low-intensity ultrasound irradiation every other day (1 MHz, 600 s) (SRP + SDT group). All rats were euthanized at 10 days postoperatively. Half of the maxilla in each group was taken for micro-CT, and the others were given the hematoxylin and eosin and Masson's trichrome examinations.

RESULTS

Both ND and D groups demonstrated less bone loss in the SRP + SDT treatment than control and SRP treatment (p < 0.05). Results of the histometric and micro-CT were the same. In addition, histological examinations showed that less bone loss was found in the SRP treatment compared to the control treatment in the D group (p < 0.05).

CONCLUSIONS

SDT was an effective therapy for ligature-induced periodontitis in rats with diabetes.

Revolutionizing oral care: Reactive oxygen species (ROS)-Regulating biomaterials for combating infection and inflammation

The human oral cavity is home to a delicate symbiosis between its indigenous microbiota and the host, the balance of which is easily perturbed by local or systemic factors, leading to a spectrum of oral diseases such as dental caries, periodontitis, and pulp infections. Reactive oxygen species (ROS) play crucial roles in the host's innate immune defenses. However, in chronic inflammatory oral conditions, dysregulated immune responses can result in excessive ROS production, which in turn exacerbates inflammation and causes tissue damage. Conversely, the potent antimicrobial properties of ROS have inspired the development of various anti-infective therapies. Therefore, the strategic modulation of ROS by innovative biomaterials is emerging as a promising therapeutic approach for oral infection and inflammation. This review begins by highlighting the state-of-the-art of ROS-regulating biomaterials, which are designed to generate, scavenge, or modulate ROS in a bidirectional manner. We then delve into the latest innovations in these biomaterials and their applications in treating a range of oral diseases, including dental caries, endodontic and periapical conditions, periodontitis, peri-implantitis, and oral candidiasis. The review concludes with an overview of the current challenges and future potential of these biomaterials in clinical settings. This review provides novel insights for the ongoing development of ROS-based therapeutic strategies for oral diseases.

Recent Advances in Basic Studies of Low-Intensity Pulsed Ultrasound in Periodontal Tissue Regeneration: A Systematic Review

Approximately half of the adult population is suffering from periodontal disease, and conventional periodontal treatment strategies can only slow the progression of the disease. As a kind of tissue engineering, periodontal regeneration brings hope for the treatment of periodontal disease. Low-intensity pulsed ultrasound (LIPUS) is a form of ultrasound with a frequency of 1-3 MHz and a much lower intensity (< 1W/cm2) than traditional ultrasound energy and output. LIPUS has been adopted for a variety of therapeutic purposes due to its bioeffects such as thermal, mechanical, and cavitation effects, which induce intracellular biochemical effects and lead to tissue repair and regeneration ultimately. In this systematic review, we summarize the basic research of LIPUS in the treatment of periodontal disease in periodontal disease animal models and the influence of LIPUS on the biological behavior (including promoting osteogenic differentiation of stem cells and inhibiting inflammatory response) and potential mechanism of periodontal ligament stem cells (PDLSCs), hoping to provide new ideas for the treatment of periodontal disease. We believe that LIPUS can be used as an auxiliary strategy in the treatment of periodontal disease and play an exciting and positive role in periodontal regeneration.

Single Atom Iron-Doped Graphic-Phase C3 N4 Semiconductor Nanosheets for Augmented Sonodynamic Melanoma Therapy Synergy with Endowed Chemodynamic Effect

Sonodynamic therapy (SDT) is a non-invasive therapeutic modality with high tissue-penetration depth to induce reactive oxygen species (ROS) generation for tumor treatment. However, the clinical translation of SDT is restricted seriously by the lack of high-performance sonosensitizers. Herein, the distinct single atom iron (Fe)-doped graphitic-phase carbon nitride (C3 N4 ) semiconductor nanosheets (Fe-C3 N4 NSs) are designed and engineered as chemoreactive sonosensitizers to effectively separate the electrons (e- ) and holes (h+ ) pairs, achieving high yields of ROS generation against melanoma upon ultrasound (US) activation. Especially, the single atom Fe doping not only substantially elevates the separation efficiency of the e- -h+ pairs involved in SDT, but also can serve as high-performance peroxidase mimetic enzyme to catalyze the Fenton reaction for generating abundant hydroxyl radicals, therefore synergistically augmenting the curative effect mediated by SDT. As verified by density functional theory simulation, the doping of Fe atom significantly promotes the charge redistribution in the C3 N4 -based NSs, which improves their synergistic SDT/chemodynamic activities. Both the in vitro and in vivo assays demonstrate that Fe-C3 N4 NSs feature an outstanding antitumor effect by aggrandizing the sono-chemodynamic effect. This work illustrates a unique single-atom doping strategy for ameliorating the sonosensitizers, and also effectively expands the innovative anticancer-therapeutic applications of semiconductor-based inorganic sonosensitizers.

Spotlight on porphyrins: Classifications, mechanisms and medical applications

Photodynamic therapy (PDT) and sonodynamic therapy (SDT) are non-invasive treatment methods with obvious inhibitory effect on tumors and have few side effects, which have been widely concerned and explored by researchers. Sensitizer is the main factor in determining the therapeutic effect of PDT and SDT. Porphyrins, a group of organic compounds widespread in nature, can be activated by light or ultrasound and produce reactive oxygen species. Therefore, porphyrins as sensitizers in PDT have been widely explored and investigated for many years. Herein, we summarize the classical porphyrin compounds and their applications and mechanisms in PDT and SDT. The application of porphyrin in clinical diagnosis and imaging is also discussed. In conclusion, porphyrins have good application prospects in disease treatment as an important part of PDT or SDT, and in clinical diagnosis and imaging.

Exosomes and ultrasound: The future of theranostic applications

Biomaterials and pertaining formulations have been very successful in various diagnostic and therapeutic applications because of its ability to overcome pharmacological limitations. Some of them have gained significant focus in the recent decade for their theranostic properties. Exosomes can be grouped as biomaterials, since they consist of various biological micro/macromolecules and possess all the properties of a stable biomaterial with size in nano range. Significant research has gone into isolation and exploitation of exosomes as potential theranostic agent. However, the limitations in terms of yield, efficacy, and target specificity are continuously being addressed. On the other hand, several nano/microformulations are responsive to physical or chemical alterations and were successfully stimulated by tweaking the physical characteristics of the surrounding environment they are in. Some of them are termed as photodynamic, sonodynamic or thermodynamic therapeutic systems. In this regard, ultrasound and acoustic systems were extensively studied for its ability towards altering the properties of the systems to which they were applied on. In this review, we have detailed about the diagnostic and therapeutic applications of exosomes and ultrasound separately, consisting of their conventional applications, drawbacks, and developments for addressing the challenges. The information were categorized into various sections that provide complete overview of the isolation strategies and theranostic applications of exosomes in various diseases. Then the ultrasound-based disease diagnosis and therapy were elaborated, with special interest towards the use of ultrasound in enhancing the efficacy of nanomedicines and nanodrug delivery systems, Finally, we discussed about the ability of ultrasound in enhancing the diagnostic and therapeutic properties of exosomes, which could be the future of theranostics.

Low‑intensity pulsed ultrasound promotes periodontal ligament stem cell migration through TWIST1‑mediated SDF‑1 expression

Low‑intensity pulsed ultrasound (LIPUS) is a non‑invasive therapeutic treatment for accelerating fracture healing. A previous study from our group demonstrated that LIPUS has the potential to promote periodontal tissue regeneration. However, the underlying molecular mechanism by which LIPUS promotes periodontal tissue regeneration remains unknown. In the present study, periodontal ligament stem cells (PDLSCs) were isolated from premolars. Flow cytometry and differentiation assays were used to characterize the isolated PDLSCs. LIPUS treatment was administered to PDLSCs, and stromal cell‑derived factor‑1 (SDF‑1) expression levels were examined by reverse transcription‑quantitative polymerase chain reaction with or without blocking the SDF‑1/C‑X‑C motif chemokine receptor 4 (CXCR4) pathway with AMD3100. ELISA was used to evaluate SDF‑1 secretion in PDLSCs. Wound healing and transwell assays were conducted to assess the migration‑promoting effect of LIPUS. A potential upstream gene of SDF‑1, twist family bHLH transcription factor 1 (TWIST1), was silenced by small interfering (si) RNA transfection. The results demonstrated that LIPUS treatment promoted the expression of TWIST1 and SDF‑1 at both the mRNA and protein levels. In addition, LIPUS treatment enhanced the cell migration of PDLSCs. Knockdown of TWIST1 impaired the expression of SDF‑1 and the cell migration ability of PDLSCs. TWIST1 may be an upstream regulator of SDF‑1 in PDLSCs. Taken together, these findings indicate that the SDF1/CXCR4 signaling pathway is involved in LIPUS‑promoted PDLSC migration, which might be one of the mechanisms for LIPUS‑mediated periodontal regeneration. TWIST1 might be a mechanical stress sensor during mechanotransduction.

Sonodynamic therapy, a treatment developing from photodynamic therapy

Sonodynamic therapy (SDT) as a new non-invasive treatment developed from photodynamic (PDT), it can kill tumor cells specifically and selectively. Moreover, recently studies showed SDT has potential to treat solid tumor, leukemia and atherosclerosis, remove proliferative scars and kill pathogenic microorganism. As SDT has an extensive application prospect, SDT has attracted more and more research recently. This thesis aims to be an informative introduction on SDT. With the assistance of related literature from 2012 to 2016, we introduce the progress of SDT research in six aspects: the therapeutic mechanism of SDT, development of the sound sensitizer, exploration of the size and frequency of ultrasonic energy, application of SDT, comparison between SDT and PDT, and current situation and future of SDT.