Photothermal effect of indocyanine green modified scaffold inhibits oral squamous cell carcinoma and promotes wound healing

A functional stent with near-infrared light triggered localized photothermal-chemo synergistic therapy for malignant stenosis of esophageal cancer

Stent implantation is a widely used palliative treatment for relieving strictures in malignant esophageal cancer. However, conventional fully covered stents play a role in preventing the tumor from ingrowth but increasing the risk of migration. Therefore, there is an urgent need for a multifunctional stent that not only reduces migration but also provides synergistic therapeutic benefits to inhibit tumor growth. This study proposed a braided esophageal stent with synergistic photothermal and chemotherapy functions to achieve precise controllable drug release. The stent was braided of Nitinol fiber and polyethylene terephthalate fiber in one-step, in which Nitinol loaded with high-efficiency photothermal conversion agent gold nanoparticles and polyethylene terephthalate loaded anti-tumor drugs release mediated by a temperature-responsive coating. The stent showed anti-migration ability and orchestrated the localized hyperthermia plus thermal-stimuli drug release during the tumor lesion. Cell experiments confirmed that the stent showed a significantly synergistic tumor cell killing effect (28.29 %). In 3D tumor sphere model, the apoptosis rate of tumor cells reached 31.34 %. In summary, the composite stent design strategy integrates anti-migration features and photoheating-controlled drug release for synergistic cancer therapy, providing a new design idea for the application of nickel-titanium alloy stents in the treatment of malignant esophageal stenosis.

Advances in Photothermal Therapy for Oral Cancer

Oral cancer represents a critical global health issue, where traditional treatment modalities are often characterized by considerable adverse effects and suboptimal effectiveness. Photothermal therapy (PTT) offers an innovative method for tumor treatment, leveraging photothermal agents to convert light into hyperthermia, ultimately leading to tumor ablation. PTT offers unique advantages in treating oral cancer due to its superficial anatomical location and consequent accessibility to laser irradiation. PTT's advantage is further enhanced by its capacity to facilitate drug release and promote tissue regeneration. Consequently, the application of PTT for oral cancer has garnered widespread interest and has undergone rapid development. This review outlines advances in PTT for oral cancer, emphasizing strategies to improve efficacy and combination therapy approaches. The key challenges, including temperature control and long-term biosafety, are discussed alongside future directions. The review also encompasses PTT's role in managing oral potentially malignant disorders and postoperative defects, conditions intimately linked with oral cancer. We aim to provide guidance for emerging PTT research in oral cancer and to promote the development of precise and efficient treatment strategies.

Mechanical properties and biocompatibility characterization of 3D printed collagen type II/silk fibroin/hyaluronic acid scaffold

Damage to articular cartilage is irreversible and its ability to heal is minimal. The development of articular cartilage in tissue engineering requires suitable biomaterials as scaffolds that provide a 3D natural microenvironment for the development and growth of articular cartilage. This study aims to investigate the applicability of a 3D printed CSH (collagen type II/silk fibroin/hyaluronic acid) scaffold for constructing cartilage tissue engineering. The results showed that the composite scaffold had a three-dimensional porous network structure with uniform pore sizes and good connectivity. The hydrophilicity of the composite scaffold was 1071.7 ± 131.6%, the porosity was 85.12 ± 1.6%, and the compressive elastic modulus was 36.54 ± 2.28 kPa. The creep and stress relaxation constitutive models were also established, which could well describe the visco-elastic mechanical behavior of the scaffold. The biocompatibility experiments showed that the CSH scaffold was very suitable for the adhesion and proliferation of chondrocytes. Under dynamic compressive loading conditions, it was able to promote cell adhesion and proliferation on the scaffold surface. The 3D printed CSH scaffold is expected to be ideal for promoting articular cartilage regeneration.

Nanomaterials-based advanced systems for photothermal / photodynamic therapy of oral cancer

The traditional clinical approaches for oral cancer consist of surgery, chemotherapy, radiotherapy, immunotherapy, and so on. However, these treatments often induce side effects and exhibit limited efficacy. Photothermal therapy (PTT) emerges as a promising adjuvant treatment, utilizing photothermal agents (PTAs) to convert light energy into heat for tumor ablation. Another innovative approach, photodynamic therapy (PDT), leverages photosensitizers (PSs) and specific wavelength laser irradiation to generate reactive oxygen species (ROS), offering an effective and non-toxic alternative. The relevant combination therapies have been reported in the field of oral cancer. Simultaneously, the advancement of nanomaterials has propelled the clinical application of PTT and PDT. Therefore, a comprehensive understanding of PTT and PDT is required for better application in oral cancer treatment. Here, we review the use of PTT and PDT in oral cancer, including noble metal materials (e.g., Au nanoparticles), carbon materials (e.g., graphene oxide), organic dye molecules (e.g., indocyanine green), organic molecule-based agents (e.g., porphyrin-analog phthalocyanine) and other inorganic materials (e.g., MXenes), exemplify the advantages and disadvantages of common PTAs and PSs, and summarize the combination therapies of PTT with PDT, PTT/PDT with chemotherapy, PTT with radiotherapy, PTT/PDT with immunotherapy, and PTT/PDT with gene therapy in the treatment of oral cancer. The challenges related to the PTT/PDT combination therapy and potential solutions are also discussed.

3D printed scaffold for repairing bone defects in apical periodontitis

Objectives

To investigate the feasibility of the 3D printed scaffold for periapical bone defects.

Methods

In this study, antimicrobial peptide KSL-W-loaded PLGA sustainable-release microspheres (KSL-W@PLGA) were firstly prepared followed by assessing the drug release behavior and bacteriostatic ability against Enterococcus faecalis and Porphyromonas gingivalis. After that, we demonstrated that KSL-W@PLGA/collagen (COL)/silk fibroin (SF)/nano-hydroxyapatite (nHA) (COL/SF/nHA) scaffold via 3D-printing technique exhibited significantly good biocompatibility and osteoconductive property. The scaffold was characterized as to pore size, porosity, water absorption expansion rate and mechanical properties. Moreover, MC3T3-E1 cells were seeded into sterile scaffold materials and investigated by CCK-8, SEM and HE staining. In the animal experiment section, we constructed bone defect models of the mandible and evaluated its effect on bone formation. The Japanese white rabbits were killed at 1 and 2 months after surgery, the cone beam computerized tomography (CBCT) and micro-CT scanning, as well as HE and Masson staining analysis were performed on the samples of the operation area, respectively. Data analysis was done using ANOVA and LSD tests. (α = 0.05).

Results

We observed that the KSL-W@PLGA sustainable-release microspheres prepared in the experiment were uniform in morphology and could gradually release the antimicrobial peptide (KSL-W), which had a long-term antibacterial effect for at least up to 10 days. HE staining and SEM showed that the scaffold had good biocompatibility, which was conducive to the adhesion and proliferation of MC3T3-E1 cells. The porosity and water absorption of the scaffold were (81.96 ± 1.83)% and (458.29 ± 29.79)%, respectively. Histological and radiographic studies showed that the bone healing efficacy of the scaffold was satisfactory.

Conclusions

The KSL-W@PLGA/COL/SF/nHA scaffold possessed good biocompatibility and bone repairing ability, and had potential applications in repairing infected bone defects.

Clinical significance The 3D printed scaffold not only has an antibacterial effect, but can also promote bone tissue formation, which provides an alternative therapy option in apical periodontitis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02362-4.