Investigating the Sonodynamic-Radiosensitivity Effect of Gold Nanoparticles on HeLa Cervical Cancer Cells

Metal-based approaches to fight cervical cancer

Cervical cancer (CC) is one of the leading causes of death among women worldwide. The current treatments for this cancer consist of invasive methods such as chemotherapeutic drugs, radiation, immunotherapy and surgery, which could lead to severe side effects and hinder the patient's life quality. Although metal-based therapies, including cisplatin and ruthenium-based compounds, offer promising alternatives, they lack specificity and harm healthy cells. Combining metal nanoparticles with standard approaches has demonstrated remarkable efficacy and safety in the fight against CC. Overall, this review is intended to show the latest advancements and insights into metal-based strategies, creating a promising path for more effective and safer treatments in the battle against CC.

Progression in low-intensity ultrasound-induced tumor radiosensitization

BACKGROUND

Radiotherapy (RT) is a widely utilized tumor treatment approach, while a significant obstacle in this treatment modality is the radioresistance exhibited by tumor cells. To enhance the effectiveness of RT, scientists have explored radiosensitization approaches, including the use of radiosensitizers and physical stimuli. Nevertheless, several approaches have exhibited disappointing results including adverse effects and limited efficacy. A safer and more effective method of radiosensitization involves low-intensity ultrasound (LIUS), which selectively targets tumor tissue and enhances the efficacy of radiation therapy.

METHODS

This review summarized the tumor radioresistance reasons and explored LIUS potential radiosensitization mechanisms. Moreover, it covered diverse LIUS application strategies in radiosensitization, including the use of LIUS alone, ultrasound-targeted intravascular microbubble destruction, ultrasound-mediated targeted radiosensitizers delivery, and sonodynamic therapy. Lastly, the review presented the limitations and prospects of employing LIUS-RT combined therapy in clinical settings, emphasizing the need to connect research findings with practical applications.

RESULTS AND CONCLUSION

LIUS employs cost-effective equipment to foster tumor radiosensitization, curtail radiation exposure, and elevate the quality of life for patients. This efficacy is attributed to LIUS's ability to utilize thermal, cavitation, and mechanical effects to overcome tumor cell resistance to RT. Multiple experimental analyses have underscored the effectiveness of LIUS in inducing tumor radiosensitization using diverse strategies. While initial studies have shown promising results, conducting more comprehensive clinical trials is crucial to confirm its safety and effectiveness in real-world situations.

High-Z elements dominated bismuth-based heterojunction nano-semiconductor for radiotherapy-enhanced sonodynamic breast cancer therapy

Ultrasound and X-rays possess remarkable tissue penetration capabilities, making them promising candidates for cancer therapy. Sonodynamic therapy, which utilizes ultrasound excitation, offers a safer alternative to radiotherapy and can be combined with X-rays to mitigate the adverse effects on normal tissues. In this study, we developed a bismuth-based heterostructure semiconductor (BFIP) to enhance the efficacy of radiotherapy and sonodynamic therapy in treating breast cancer. The semiconductor is fabricated through a two-step process involving the synthesis of porous spherical bismuth fluoride and partially reduced to bismuth oxyiodide. Then, followed by surface modification with amphiphilic polyethylene glycol, BFIP is fabricated. Incorporating heavy atoms in the BFIP enhances radiosensitivity. The BFIP exhibits superior carrier separation efficiency compared to bismuth fluoride, generating a substantial quantity of reactive oxygen species upon ultrasound stimulation. Moreover, the BFIP effectively depletes glutathione through coordination and hole-mediated oxidation pathways, disrupting the tumor microenvironment and inducing oxidative stress. Encouraging results are acquired in both in vitro cell and in vivo tumor models. Our study provides a de-risking strategy by utilizing ultrasound as a partial substitute for X-rays in treating deep-seated tumors, offering a viable research direction for constructing a unified nanoplatform.

Kinetic modelling of ultrasound-triggered chemotherapeutic drug release from the surface of gold nanoparticles

Therapeutic ultrasound can be used to trigger the on-demand release of chemotherapeutic drugs from gold nanoparticles (GNPs). In the previous work, our group achieved doxorubicin (DOX) release from the surface of GNPS under low-intensity pulsed ultrasound (LIPUS) exposure. However, the specific release kinetics of ultrasound-triggered DOX release from GNPs is not known. Here, we present a release kinetics study of DOX from GNPs under ultrasound exposure for the first time. A novel dialysis membrane setup was designed to quantify DOX release from LIPUS-activated GNPs at 37.0 °C and 43.4 °C (hyperthermia temperature range). Contributions of thermal and non-thermal mechanisms of LIPUS-triggered DOX release were also quantified. Non-thermal mechanisms accounted for 40 ± 7% and 34 ± 5% of DOX release for 37.0 °C and 43.4 °C trials, respectively. DOX release under LIPUS exposure was found to follow Korsmeyer-Peppas (K-P) kinetics, suggesting a shift from a Fickian (static) to a non-Fickian (dynamic) release profile with the addition of non-thermal interactions. DOX release was attributed to an anomalous diffusion release mechanism from the GNP surface. A finite element model was also developed to quantify the acoustic radiation force, believed to be the driving force of non-thermal DOX release inside the dialysis bag.

Low-intensity pulsed ultrasound in obstetrics and gynecology: advances in clinical application and research progress

In the past decade, research on ultrasound therapy in obstetrics and gynecology has rapidly developed. Currently, high-intensity ultrasound has been widely used in clinical practice, while low-intensity ultrasound has gradually emerged as a new trend of transitioning from pre-clinical research to clinical applications. Low-intensity pulsed ultrasound (LIPUS), characterized by a non-invasive low-intensity pulse wave stimulation method, employs its non-thermal effects to achieve safe, economical, and convenient therapeutic outcomes. LIPUS converts into biochemical signals within cells through pathways such as cavitation, acoustic flow, and mechanical stimulation, regulating molecular biological mechanisms and exerting various biological effects. The molecular biology mechanisms underlying the application of LIPUS in obstetrics and gynecology mainly include signaling pathways, key gene expression, angiogenesis, inflammation inhibition, and stem cell differentiation. LIPUS plays a positive role in promoting soft tissue regeneration, bone regeneration, nerve regulation, and changes in cell membrane permeability. LIPUS can improve the treatment benefit of premature ovarian failure, pelvic floor dysfunction, nerve damage caused by intrauterine growth restriction, ovariectomized osteoporosis, and incomplete uterine involution through the above biological effects, and it also has application value in the adjuvant treatment of malignant tumors such as ovarian cancer and cervical cancer. This study outlines the biological mechanisms and applications of LIPUS in treating various obstetric and gynecologic diseases, aiming to promote its precise application and provide a theoretical basis for its use in the field.

ROS-generating alginate-coated gold nanorods as biocompatible nanosonosensitisers for effective sonodynamic therapy of cancer

Sonodynamic therapy (SDT) emerges as a promising non-invasive alternative for eradicating malignant tumours. However, its therapeutic efficacy remains limited due to the lack of sonosensitisers with high potency and biosafety. Previously, gold nanorods (AuNRs) have been extensively studied for their applications in photodynamic or photothermal cancer therapy, but their sonosensitising properties are largely unexplored. Here, we reported the applicability of alginate-coated AuNRs (AuNRs^ALG) with improved biocompatibility profiles as promising nanosonosensitisers for SDT for the first time. AuNRs^ALG were found stable under ultrasound irradiation (1.0 W/cm², 5 min) and maintained structural integrity for 3 cycles of irradiation. The exposure of the AuNRs^ALG to ultrasound irradiation (1.0 W/cm², 5 min) was shown to enhance the cavitation effect significantly and generate a 3 to 8-fold higher amount of singlet oxygen (¹O₂) than other reported commercial titanium dioxide nanosonosensitisers. AuNRs^ALG exerted dose-dependent sonotoxicity on human MDA-MB-231 breast cancer cells in vitro, with ∼ 81% cancer cell killing efficacy at a sub-nanomolar level (IC₅₀ was 0.68 nM) predominantly through apoptosis. The protein expression analysis showed significant DNA damage and downregulation of anti-apoptotic Bcl-2, suggesting AuNRs^ALG induced cell death through the mitochondrial pathway. The addition of mannitol, a reactive oxygen species (ROS) scavenger, inhibited cancer-killing effect of AuNRs^ALG-mediated SDT, further verifying that the sonotoxicity of AuNRs^ALG is driven by the production of ROS. Overall, these results highlight the potential application of AuNRs^ALG as an effective nanosonosensitising agent in clinical settings.

Mapping knowledge landscapes and emerging trends of sonodynamic therapy: A bibliometric and visualized study

Background: Ultrasound-triggered sonodynamic therapy (SDT), as a non-invasive approach, has attracted considerable attention in a wide variety of malignant tumors and other diseases. Over the past 2 decades, the number of scientific publications on SDT has increased rapidly. However, there is still a lack of one comprehensive report that summarizes the global research trends and knowledge landscapes in the field of SDT in detail. Thus, we performed a bibliometric analysis on SDT from 2000 to 2021 to track the current hotspots and highlight future directions. Methods: We collected publications on SDT research from the Web of Science Core Collection database. The annual number of publications and citations, major contributors, popular journals, international collaborations, co-cited references and co-occurrence keywords were analyzed and visualized with CiteSpace, VOSviewer, and R-bibliometrix. Results: A total of 701 publications were included. The annual publication output increased from 5 in 2000 to 175 in 2021, and the average growth rate was 18.4%. China was the most productive country with 463 documents (66.05%), and Harbin Medical University was the most prolific institution (N = 73). Ultrasound in Medicine and Biology published the most papers related to SDT. Materials Science, and Chemistry were the research areas receiving the most interest. All the keywords were divided into four different clusters including studies on mechanisms, studies on drug delivery and nanoparticles, studies on cancer therapy, as well as studies on ultrasound and sonosensitizers. In addition to nanomaterials-related studies including nanoparticles, mesoporous silica nanoparticles, nanosheets, liposomes, microbubble and TiO₂ nanoparticle, the following research directions such as immunogenic cell death, metal-organic framework, photothermal therapy, hypoxia, tumor microenvironment, chemodynamic therapy, combination therapy, tumor resistance, intensity focused ultrasound, drug delivery, and Staphylococcus aureus also deserve further attention and may continue to explode in the future. Conclusion: SDT has a bright future in the field of cancer treatment, and nanomaterials have increasingly influenced the SDT field with the development of nano-technology. Overall, this comprehensive bibliometric study was the first attempt to analyze the field of SDT, which could provide valuable references for later researchers to better understand the global research trends, hotspots and frontiers in this domain.

Mechanical and antibacterial efficacy of photo-sonodynamic therapy via methylene blue-loaded nanoparticles over dental implants for treating peri-implantitis

AIM

This study aimed to evaluate the mechanical (i.e., flexural modulus [FM], flexural strength [FS], and surface roughness [R_a]) and antibacterial efficacy of photo-sonodynamic therapy via methylene blue-loaded poly(D,L-lactide-co-glycolide) nanoparticles (MB-loaded PLGA NPs) over dental implants for potential treatment of peri-implantitis.

METHODS

PLGA NPs were synthesized via a solvent displacement method. After the synthesis and confirmation of MB-loaded PLGA NPs via physical (Scanning Electron Microscope [SEM]) and chemical characterization (Fourier transform infrared spectroscopy [FTIR]), the mature dental biofilm of Porphyromonas gingivalis was produced over the surfaces of dental implants. Then, the bacterial viability assessment of the following five study groups was performed: group-I (diode laser treatment); group-II (PDT/MB-loaded PLGA NPs treatment; group-III (ultrasound treatment); group-IV (ultrasound/PLGA NPs-MB treatment); and group-V: control group included the samples without any treatment. Finally, the FS, FM, and R_a of the samples was assessed.

RESULTS

Under the SEM, the NPs were spherical homogeneous particles having round morphology ranging approximately 100 nm in size without aggregation. The FTIR spectra of PLGA NPs and MB-loaded PLGA NPs demonstrated absorption peaks at approximately 1000 cm^-1 to 1200 cm^-1 and around 1500 cm^-1 to 1750 cm^-1. The greatest level of P. gingivalis killing was exhibited by ultrasound/MB-loaded PLGA-NPs-treated samples. The FS was statistically significantly greater for control group samples than any other group (i.e., 100.28 MPa; p<0.05). The FM and R_a ranged between 3.31 and 3.58 GPa and between 0.18 and 0.20 µm without any statistically significant difference between the control and experimental groups (p>0.05), respectively.

CONCLUSION

Within the limitations of this study, the application of photo-sonodynamic therapy via MB-loaded PLGA NPs demonstrated the greatest antibacterial activity against P. gingivalis without deteriorating the surfaces and compromising the mechanical properties of dental implants.

Multifunctional high-Z nanoradiosensitizers for multimodal synergistic cancer therapy

Radiotherapy (RT) is one of the most common and effective clinical therapies for malignant tumors. However, there are several limitations that undermine the clinical efficacy of cancer RT, including the low X-ray attenuation coefficient of organs, serious damage to normal tissues, and radioresistance in hypoxic tumors. With the rapid development of nanotechnology and nanomedicine, high-Z nanoradiosensitizers provide novel opportunities to overcome radioresistance and improve the efficacy of RT by deposition of radiation energy through photoelectric effects. To date, several types of nanoradiosensitizers have entered clinical trials. Nevertheless, the limitation of the single treatment mode and the unclear mechanism of nanoparticle radiosensitization have hindered the further development of nanoradiosensitizers. In this review, we systematically describe the interaction mechanisms between X-rays and nanomaterials and summarize recent advances in multifunctional high-Z nanomaterials for radiotherapeutic-based multimodal synergistic cancer therapy. Finally, the challenges and prospects are discussed to stimulate the development of nanomedicine-based cancer RT.

Sonodynamic therapy: Ultrasound parameters and in vitro experimental configurations

Sonodynamic therapy (SDT) is a new therapeutic modality for noninvasive cancer treatment based on the association of ultrasound and sonosensitizer drugs. Up to date, there is not a consensus on the standardization of the experimental conditions for the in vitro studies to correctly assess cell viability during SDT. Therefore, this review article mainly describes how the main ultrasound parameters and experimental setups of ultrasound application in vitro studies can influence the SDT bioeffects/response. The sonodynamic action is impacted by the combination of frequency, intensity, duty cycle, and ultrasound application time. The variation of experimental setups in cell culture, such as the transducer position, cell-transducer distance, coupling medium thickness, or type of culture, also influences the sonodynamic response. The intensity, duty cycle, and sonication duration increase cytotoxicity and reactive oxygen species production. For similar ultrasound parameters, differences in the experimental configuration impact cell death in vitro. Four main experimental setups are used to assess for SDT in cell culture (i) a planar transducer placed directly in contact with the bottom of the culture microplate; (ii) microplate positioned in the transducer's far-field using a water tank; (iii) sealed cell culture tubes immersed in water away from the transducer; and (iv) transducer dipped directly into the well with cell culture. Because of the significant variations in the experimental setups, sonodynamic response can significantly vary, and the translation of these results for in vivo experimentation is difficult. Therefore, a well-designed and detailed in vitro experimental setup is vital for understanding the interactions among the biological medium, the sonosensitizer, and the ultrasound for the in vitro to in vivo translation in SDT.

Recent progress in sono-photodynamic cancer therapy: From developed new sensitizers to nanotechnology-based efficacy-enhancing strategies

Many sensitizers have not only photodynamic effects, but also sonodynamic effects. Therefore, the combination of sonodynamic therapy (SDT) and photodynamic therapy (PDT) using sensitizers for sono-photodynamic therapy (SPDT) provides alternative opportunities for clinical cancer therapy. Although significant advances have been made in synthesizing new sensitizers for SPDT, few of them are successfully applied in clinical settings. The anti-tumor effects of the sensitizers are restricted by the lack of tumor-targeting specificity, incapability in deep intratumoral delivery, and the deteriorating tumor microenvironment. The application of nanotechnology-based drug delivery systems (NDDSs) can solve the above shortcomings, thereby improving the SPDT efficacy. This review summarizes various sensitizers as sono/photosensitizers that can be further used in SPDT, and describes different strategies for enhancing tumor treatment by NDDSs, such as overcoming biological barriers, improving tumor-targeted delivery and intratumoral delivery, providing stimuli-responsive controlled-release characteristics, stimulating anti-tumor immunity, increasing oxygen supply, employing different therapeutic modalities, and combining diagnosis and treatment. The challenges and prospects for further development of intelligent sensitizers and translational NDDSs for SPDT are also discussed.

Nanoparticle-based applications for cervical cancer treatment in drug delivery, gene editing, and therapeutic cancer vaccines

Cervical cancer is a leading cause of gynecological tumor related deaths worldwide. The applications of conventional approaches such as chemoradiotherapy and surgery are restricted due to their side effects and drug resistances. Although immune checkpoint inhibitors (ICIs) have emerged as novel choices, their clinical response rates are rather limited. To date there is a lack of effective treatment regimens for patients with metastatic or recurrent cervical cancer. Recently nanomaterials like liposomes, dendrimers, and polymers are considered as promising delivery carriers with advantages of tumor‐specific administration, reduced toxicity, and improved biocompatibility. Here, we review the applications of nanoparticles in the fields of drug delivery, CRISPR based genome‐editing and therapeutic vaccines in cervical cancer treatment.

This article is categorized under:

Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease

Modulation of the triggered apoptosis by nano emodin transfersome-mediated sonodynamic therapy on head and neck squamous cell carcinoma cell lines

BACKGROUND

Non-invasive sonodynamic therapy (SDT) is a new treatment modality that uses low-intensity ultrasound to activate a non-toxic sensitizing chemical agent for cancer therapy in a site-directed manner. This study aimed to investigate the anti-cancer effects of ultrasound combined with nano emodin transfersome (NET) on head and neck squamous cell carcinoma (HNSCC) cell lines.

MATERIALS AND METHODS

A transfersome form of nano emodin as a novel sono-responsive nanomaterial was synthesized to enhance the accumulation and penetration of nanoparticles. iIn vitro experiments including hemolytic activity, cell proliferation, intracellular reactive oxygen species (ROS) generation, apoptosis induction, DNA fragmentation, and mRNA expressions of caspase 3 and 9 were conducted to explore the anti-cancer effects of NET-SDT on FaDu and CAL-27 cell lines.

RESULTS

Characterization tests showed the round and uniform morphology of NET with transfersome structure, resulting in a high drug-loading content and encapsulation efficiency. No significant hemolytic activity was observed (P > 0.05). Cytotoxicity gradually increased with increasing concentrations of NET, so that 10 × 10^-4 g/L of NET plus 5 min ultrasound irradiation at a frequency of 1 MHz and ultrasonic intensity of 2 W/cm² effectively killed 98.2 % and 97.3 % of FaDu and CAL-27 cell lines, respectively (P < 0.05). We found that ROS generation in NET-SDT was dose-dependent and the triggered apoptosis and caspase-3/9 gene expression levels were significantly enhanced as the concentration of NET increased (P < 0.05). No significant difference was found in the rate of apoptosis induction and gene expression between two cell lines.

CONCLUSIONS

Our data demonstrated that SDT with NET as a sonosensitizer can induce apoptosis and significantly decrease cell viability of HNSCC cell lines, which represents the role of NET-SDT as a potent anti-cancer modality.

External and Internal Stimuli-Responsive Metallic Nanotherapeutics for Enhanced Anticancer Therapy

Therapeutic, diagnostic, and imaging approaches based on nanotechnology offer distinct advantages in cancer treatment. Various nanotherapeutics have been presented as potential alternatives to traditional anticancer therapies such as chemotherapy, radiotherapy, and surgical intervention. Notably, the advantage of nanotherapeutics is mainly attributable to their accumulation and targeting ability toward cancer cells, multiple drug-carrying abilities, combined therapies, and imaging approaches. To date, numerous nanoparticle formulations have been developed for anticancer therapy and among them, metallic nanotherapeutics reportedly demonstrate promising cancer therapeutic and diagnostic efficiencies owing to their dense surface functionalization ability, uniform size distribution, and shape-dependent optical responses, easy and cost-effective synthesis procedure, and multiple anti-cancer effects. Metallic nanotherapeutics can remodel the tumor microenvironment by changing unfavorable therapeutic conditions into therapeutically accessible ones with the help of different stimuli, including light, heat, ultrasound, an alternative magnetic field, redox, and reactive oxygen species. The combination of metallic nanotherapeutics with both external and internal stimuli can be used to trigger the on-demand release of therapeutic molecules, augmenting the therapeutic efficacies of anticancer therapies such as photothermal therapy, photodynamic therapy, magnetic hyperthermia, sonodynamic therapy, chemodynamic therapy, and immunotherapy. In this review, we have summarized the role of different metallic nanotherapeutics in anti-cancer therapy, as well as their combinational effects with multiple stimuli for enhanced anticancer therapy.

In Vitro Application of Sonodynamic Antimicrobial Chemotherapy as a Sonobactericidal Therapeutic Approach for Bacterial Infections: A Systematic Review and Meta-analysis

Introduction: This study aimed to perform a systematic review of the literature followed by a meta-analysis about the efficacy of sonodynamic antimicrobial chemotherapy (SACT) in bacterial infections. Methods: According to the PICOS (population, intervention, comparison and outcome) recommendations and PRISMA guidelines, an electronic search was conducted in PubMed, SCOPUS, Embase, and Cochrane Library based on the MeSH terms. All analyses were conducted using Biostat's Comprehensive Meta-Analysis version 2.0. The inter-study heterogeneity and publication bias assessments were carried out on the studies using I2 and the Egger's regression test. Results: Initially, 126 articles were identified in the electronic search, and 14 studies remained after analysis and exclusion of the duplicated studies and eligibility criteria. All results from the included studies displayed a significant reduction of microorganisms. The meta-analysis demonstrated a significant reduction in the bacterial load in all analyses (0.944% [95% CI, 0.901-0.969%; P=0.000]). Also, there was a low risk of bias for microbial load reduction without the evidence of publication bias. Conclusion: The results highlight that there is scientific evidence emphasizing the effectiveness of SACT in reducing the count of microorganisms in bacterial infections.

Enhanced Radiosensitization for Cancer Treatment with Gold Nanoparticles through Sonoporation

We demonstrate the megavoltage (MV) radiosensitization of a human liver cancer line by combining gold-nanoparticle-encapsulated microbubbles (AuMBs) with ultrasound. Microbubbles-mediated sonoporation was administered for 5 min, at 2 h prior to applying radiotherapy. The intracellular concentration of gold nanoparticles (AuNPs) increased with the inertial cavitation of AuMBs in a dose-dependent manner. A higher inertial cavitation dose was also associated with more DNA damage, higher levels of apoptosis markers, and inferior cell surviving fractions after MV X-ray irradiation. The dose-modifying ratio in a clonogenic assay was 1.56 ± 0.45 for a 10% surviving fraction. In a xenograft mouse model, combining vascular endothelial growth factor receptor 2 (VEGFR2)-targeted AuMBs with sonoporation significantly delayed tumor regrowth. A strategy involving the spatially and temporally controlled release of AuNPs followed by clinically utilized MV irradiation shows promising results that make it worthy of further translational investigations.

Remotely Activated Nanoparticles for Anticancer Therapy

Cancer has nowadays become one of the leading causes of death worldwide. Conventional anticancer approaches are associated with different limitations. Therefore, innovative methodologies are being investigated, and several researchers propose the use of remotely activated nanoparticles to trigger cancer cell death. The idea is to conjugate two different components, i.e., an external physical input and nanoparticles. Both are given in a harmless dose that once combined together act synergistically to therapeutically treat the cell or tissue of interest, thus also limiting the negative outcomes for the surrounding tissues. Tuning both the properties of the nanomaterial and the involved triggering stimulus, it is possible furthermore to achieve not only a therapeutic effect, but also a powerful platform for imaging at the same time, obtaining a nano-theranostic application. In the present review, we highlight the role of nanoparticles as therapeutic or theranostic tools, thus excluding the cases where a molecular drug is activated. We thus present many examples where the highly cytotoxic power only derives from the active interaction between different physical inputs and nanoparticles. We perform a special focus on mechanical waves responding nanoparticles, in which remotely activated nanoparticles directly become therapeutic agents without the need of the administration of chemotherapeutics or sonosensitizing drugs.

Sonodynamic therapy-derived multimodal synergistic cancer therapy

Sonodynamic therapy (SDT) represents a promising modality that provides the possibility of non-invasively eliminating solid tumors in a site-directed manner. In light of the complexity and heterogeneity of tumors, more and more studies are attempting to combine SDT with other therapeutic methods so as to achieve better tumor treatment effect, which sheds new light on the potential of SDT-based synergistic therapeutics. Herein, the representative studies of SDT-instructed multimodal synergistic cancer therapy are comprehensively presented, such as sono-chemotherapy, sono-radiotherapy, sono-immunotherapy, and sono-chemodynamic therapy, etc., and their incorporate mechanisms are discussed in detail. The current challenges and future prospects to promote the advanced development of SDT-based nanomedicines in this burgeoning research field are highlighted. It is believed that such an emerging synergistic therapeutic modality based on SDT will play a more significant role in the field of tumor precision treatment medicine.

Photo-sonodynamic antimicrobial chemotherapy via chitosan nanoparticles-indocyanine green against polymicrobial periopathogenic biofilms: Ex vivo study on dental implants

BACKGROUND

Antimicrobial photodynamic therapy (aPDT) is a treatment to deal with microorganisms, which is limited to treating microbial biofilms due to poor light penetration. Sonodynamic antimicrobial chemotherapy (SACT) can be used for circumventing the limitations of aPDT to inhibit the polymicrobial biofilms. The objective of this study has been focused on the simultaneous use of aPDT and SACT, which is called photo-sonodynamic antimicrobial chemotherapy (P-SACT) to inhibit the biofilms of periopathogens bacteria on surfaces of the titanium dental implants.

MATERIALS AND METHODS

Following synthesis and confirmation of Chitosan Nanoparticles-Indocyanine green (CNPs-ICG) as photo-sonosensitizer, the mature biofilm model of the polymicrobial synergism of periopathogens was formed on the surface of the titanium dental implants. The quantitative and qualitative evaluations of periopathogens biofilms were performed using microbial viability and scanning electron microscopy analysis of the following groups of treatment modalities (n = 5): 1- Control (periopathogens biofilm without treatment), 2- ICG, 3- CNPs-ICG, 4- diode laser, 5- aPDT/ICG, 6- aPDT/CNPs-ICG, 7- ultrasound, 8- SACT/ICG, 9- SACT/CNPs-ICG, 10- PSACT/ICG, 11- PSACT/CNPs-ICG, and 12-0.2% chlorhexidine (CHX).

RESULTS

A significant reduction in the log₁₀ CFU/mL of periopathogens was observed in the groups treated with aPDT/ICG, aPDT/CNPs-ICG, SACT/ICG, SACT/CNPs-ICG, PSACT/ICG, PSACT/CNPs-ICG, and 0.2% CHX up to 5.3, 6.5, 5.6, 6.6, and 8.8 log, respectively, when compared with control group (P < 0.05). PSACT/CNPs-ICG group demonstrated significantly higher capacity in eliminating the periopathogens biofilm compared with other groups (P < 0.05). However, there was no significant difference between PSACT/CNPs-ICG and 0.2% CHX (P > 0.05). Microscopic images revealed that biofilms treated with PSACT were comprised mainly of deformed and dead cells.

CONCLUSIONS

These results highlight the potential of PSACT/CNPs-ICG for the decontamination of the dental implant surfaces from the polymicrobial synergism of periopathogens biofilm.

Effect of targeted gold nanoparticles size on acoustic cavitation: An in vitro study on melanoma cells

When a liquid is irradiated with high intensities of ultrasound irradiation, acoustic cavitation occurs. Since cavitation can be fatal to cells, it is utilized to destroy cancer tumors. Considering cavitation onset and bubbles collapse, the required ultrasonic intensity threshold can be significantly decreased in the presence of nanoparticles in a liquid. The effects of gold nanoparticles size on acoustic cavitation were investigated in this in vitro study. For this purpose, ultrasonic waves were used at intensities of 0.5, 1 and 2 W/cm² and frequency of 1 MHz in the presence of F-Cys-GNPs with 15, 23 and 79 nm sizes and different concentrations (0.2, 1 and 5 µg/ml) in order to determine their effects on the viability of melanoma cells. This was performed at different incubation times 12, 24 and 36 h. The viability of melanoma cells decreased at higher concentrations and sizes of F-Cys-GNPs. The lowest viability of melanoma cells was seen in those containing 79, 23, and 15 nm F-Cys-GNPs. This finding could be explained from the concept that the nucleation sites on the surface of GNPs increase with an increase in size of GNPs, which results in an increase in the number of cavitation bubbles. Acoustic cavitation in the presence of gold nanoparticles can be used as a way for improving therapeutic effects on the tumors.