Laser immunotherapy (LIT) is being developed as a treatment modality for metastatic cancer which can destroy primary tumors and induce effective systemic anti-tumor responses by using a targeted treatment approach in conjunction with the use of a novel immunoadjuvant, glycated chitosan (GC). In this study, Non-invasive Laser Immunotherapy (NLIT) was used as the primary treatment mode. We incorporated single-walled carbon nanotubes (SWNTs) into the treatment regimen to boost the tumor-killing effect of LIT. SWNTs and GC were conjugated to create a completely novel, immunologically modified carbon nanotube (SWNT-GC). To determine the efficacy of different laser irradiation durations, 5 minutes or 10 minutes, a series of experiments were performed. Rats were inoculated with DMBA-4 cancer cells, a highly aggressive metastatic cancer cell line. Half of the treatment group of rats receiving laser irradiation for 10 minutes survived without primary or metastatic tumors. The treatment group of rats receiving laser irradiation for 5 minutes had no survivors. Thus, Laser+SWNT-GC treatment with 10 minutes of laser irradiation proved to be effective at reducing tumor size and inducing long-term anti-tumor immunity.
The microenvironments of tumors are involved in a complex and reciprocal dialog with surrounding cancer cells. Any novel treatment must consider the impact of the therapy on the microenvironment. Recently, clinical trials with laser immunotherapy (LIT) have proven to effectively treat patients with late-stage, metastatic breast cancer and melanoma. LIT is the synergistic combination of phototherapy (laser irradiation) and immunological stimulation. One prominent cell type found in the tumor stroma is the fibroblast. Fibroblast cells can secrete different growth factors and extracellular matrix modifying molecules. Furthermore, fibroblast cells found in the tumor stroma often express alpha smooth muscle actin. These particular fibroblasts are coined cancer-associated fibroblast cells (CAFs). CAFs are known to facilitate the malignant progression of tumors. A collagen lattice assay with human fibroblast cells is used to elucidate the effects LIT has on the microenvironment of tumors. Changes in the contraction of the lattice, the differentiation of the fibroblast cells, as well as the proliferation of the fibroblast cells will be determined.
Laser immunotherapy (LIT) is an innovative cancer modality that uses laser irradiation and immunological stimulation to treat late-stage, metastatic cancers. The current mode of operation in LIT is through interstitial laser irradiation. Although LIT is still in development, recent clinical trials have shown that it can be used to successfully treat patients with late-stage breast cancer and melanoma. Cyclophosphamide is a chemotherapy drug that suppresses regulatory T cells when used in low doses. In this study tumor-bearing rats were treated with LIT using an 805-nm laser with a power of 2.0 W and low-dose cyclophosphamide. Glycated chitosan was used as an immunological stimulant. The goal was to observe the effects of different doses of cyclophosphamide in addition to LIT on the survival of the tumor-bearing rats.
Combining near infrared (NIR) laser irradiation into a tumor treatment therapy has shown promising results. For a comprehensive tumor therapy, it is important to understand the effects of NIR irradiation not only on the tumor, but on the tumor stroma as well. The composition of the microenvironment present near the tumor cells is critical to the phenotype of the tumor. Fibroblasts affect tissue homeostasis and change the microenvironment surrounding the tumor. Myofibroblast are derived from fibroblast cells, and in some cases indicate the transformation of healthy tissue into malignant tissue. Wound healing environments are rich in fibroblast cells and are similar to tumor stromas. To simulate a tumor stroma a wound healing environment was constructed. Two different human fibroblast cells were cultured in collagen lattices. Specifically, collagen lattices were created, with type 1 collagen, incubated for 5 days and irradiated with a 980nm laser on the 4th day. The subsequent collagen lattices were either released and measured, or fixed for immunostaining on the 5th day; the contraction rates also were analyzed. Furthermore, collagen lattices were stained to identify fibroblast proliferation and differentiation, into myofibroblasts. The results suggested NIR laser irradiation had some biological effects on the fibroblast cells, but the full extent of the effects is still unclear.
While successes of different cancer therapies have been achieved in various degrees a systemic immune
response is needed to effectively treat late-stage, metastatic cancers, and to establish long-term tumor
resistance in the patients. A novel method for combating metastatic cancers has been developed using
immunologically modified carbon nanotubes in conjunction with phototherapy. Glycated chitosan (GC) is a
potent immunological adjuvant capable of increasing host immune responses, including antigen presentation
by activation of dendritic cells (DCs) and causing T cell proliferation. GC is also an effective surfactant for
nanomaterials. By combining single-walled carbon nanotubes (SWNTs) and GC, immunologically modified
carbon nanotubes (SWNT-GC) were constructed. The SWNT-GC suspension retains the enhanced light
absorption properties in the near infrared (NIR) region and the ability to enter cells, which are characteristic
of SWNTs. The SWNT-GC also retains the immunological properties of GC. Cellular SWNT-GC
treatments increased macrophage activity, DC activation and T cell proliferation. When cellular SWNT-GC
was irradiated with a laser of an appropriate wavelength, these immune activities could be enhanced. The
combination of laser irradiation and SWNT-GC induced cellular toxicity in targeted tumor cells, leading to a
systemic antitumor response. Immunologically modified carbon nanotubes in conjunction with
phototherapy is a novel and promising method to produce a systemic immune response for the treatment of