Biodistribution and efficacy studies of Chitosan-photosensitiser nanoconjugates encapsulating ferroptosis inducer as a anticancer therapy
1 Purpose
Anticancer drug delivery through biodegradable nanoparticles (NPs), triggered to release their content in the vicinity of the tumor is supposed to enhance the local concentration of drugs and reduce the side effects. We have developed biodegradable chitosan-photosensitizer NPs loaded with a ferroptosis-inducing drug. NPs have been characterized and display good physicochemical properties and high drug loading capacity and drug retainment. They have been tested for uptake, drug release and cytotoxicity in cell culture with and without light-induced photochemical internalization (PCI), and it is now necessary to test their efficacy in vivo. In this study, we want to investigate if incorporation of ferroptosis inducer in the NPs can inhibit breast cancer tumor growth and reduce adverse effects in healthy tissue when compared to drug alone. In addition, we want to test if the light-induced photodynamic therapy/internalization can further increase the delivery of the nanoparticles to the tumor cells and thereby enhance the anti-tumor effect of the drugs. It would also be of interest to explore whether the PDT treatment will enhance uptake and efficacy of the ferroptosis inhibitor given as a free drug. Moreover, we aim to clarify, the effect of illumination on the composition of immune cells within tumors.
2 Distress
Biodistribution study involves intravenous injection of NPs, and in vivo imaging after providing anesthesia in tumor-bearing mice. This may cause mild stress to the animals. Mice models of breast cancer will be implanted bilaterally and subcutaneously near to the mammary fat pad. This involves surgical procedures, with prior anesthesia and analgesia. The growing tumors may cause discomforts and may impair normal movement when the tumors are large. However, the animals will be euthanized before the tumor reaches the maximum size of 15mm or 1700mm3 in diameter ensuring no severe harm. Animals will receive treatment with a free drug or drug-loaded NPs, which can result in loss of body weight and the animals may experience discomforts of chemotherapy. The dose to be used in biodistribution and efficacy studies will be adjusted according to results obtained in initial dose-escalation investigations a well-tolerated dose will be administered.
3 Expected benefit
The study will provide a direct pre-clinical analysis of the NPs with and without encapsulated ferroptosis inducer, which may form the basis for their future clinical applications. It may also provide leads to develop improved forms of these NPs for cancer therapy.
4 Number of animals, and what kind
We apply for total of 558 athymic nude mice and C57BL/6 or Balb/C mice.
5 How to adhere to 3R
We aim to replace and reduce the number of animals and will always try to refine the procedures. The efficacy of cancer treatment and the distribution of NPs and drugs in an organism is complex and there are no validated alternative techniques available to date to test these effects in an efficient manner. Number of mice proposed is kept as low as possible, but high enough not to compromise the scientific quality of the experiment and statistical analysis of the results.
Anticancer drug delivery through biodegradable nanoparticles (NPs), triggered to release their content in the vicinity of the tumor is supposed to enhance the local concentration of drugs and reduce the side effects. We have developed biodegradable chitosan-photosensitizer NPs loaded with a ferroptosis-inducing drug. NPs have been characterized and display good physicochemical properties and high drug loading capacity and drug retainment. They have been tested for uptake, drug release and cytotoxicity in cell culture with and without light-induced photochemical internalization (PCI), and it is now necessary to test their efficacy in vivo. In this study, we want to investigate if incorporation of ferroptosis inducer in the NPs can inhibit breast cancer tumor growth and reduce adverse effects in healthy tissue when compared to drug alone. In addition, we want to test if the light-induced photodynamic therapy/internalization can further increase the delivery of the nanoparticles to the tumor cells and thereby enhance the anti-tumor effect of the drugs. It would also be of interest to explore whether the PDT treatment will enhance uptake and efficacy of the ferroptosis inhibitor given as a free drug. Moreover, we aim to clarify, the effect of illumination on the composition of immune cells within tumors.
2 Distress
Biodistribution study involves intravenous injection of NPs, and in vivo imaging after providing anesthesia in tumor-bearing mice. This may cause mild stress to the animals. Mice models of breast cancer will be implanted bilaterally and subcutaneously near to the mammary fat pad. This involves surgical procedures, with prior anesthesia and analgesia. The growing tumors may cause discomforts and may impair normal movement when the tumors are large. However, the animals will be euthanized before the tumor reaches the maximum size of 15mm or 1700mm3 in diameter ensuring no severe harm. Animals will receive treatment with a free drug or drug-loaded NPs, which can result in loss of body weight and the animals may experience discomforts of chemotherapy. The dose to be used in biodistribution and efficacy studies will be adjusted according to results obtained in initial dose-escalation investigations a well-tolerated dose will be administered.
3 Expected benefit
The study will provide a direct pre-clinical analysis of the NPs with and without encapsulated ferroptosis inducer, which may form the basis for their future clinical applications. It may also provide leads to develop improved forms of these NPs for cancer therapy.
4 Number of animals, and what kind
We apply for total of 558 athymic nude mice and C57BL/6 or Balb/C mice.
5 How to adhere to 3R
We aim to replace and reduce the number of animals and will always try to refine the procedures. The efficacy of cancer treatment and the distribution of NPs and drugs in an organism is complex and there are no validated alternative techniques available to date to test these effects in an efficient manner. Number of mice proposed is kept as low as possible, but high enough not to compromise the scientific quality of the experiment and statistical analysis of the results.