Cold atmospheric pressure plasmas (APP) have been reported to selectively kill cancer cells without damaging the surrounding tissues. Studies have been conducted on a variety of cancer types but to the best of our knowledge not on any kind of bone cancer. Treatment options for...
Cold atmospheric pressure plasmas (APP) have been reported to selectively kill cancer cells without damaging the surrounding tissues. Studies have been conducted on a variety of cancer types but to the best of our knowledge not on any kind of bone cancer. Treatment options for bone cancer include surgery, chemotherapy, etc. and may involve the use of bone grafting biomaterials to replace the surgically removed bone.
APACHE brings a totally different and ground-breaking approach in the design of a novel therapy for bone cancer by taking advantage of the active species generated by APP in combination with biomaterials to deliver the active species locally in the diseased site. The feasibility of this approach is rooted in the evidence that the cellular effects of APP appear to strongly involve the suite of reactive species created by plasmas, which can be derived from a) direct treatment of the malignant cells by APP or b) indirect treatment of the liquid media by APP which is then put in contact with the cancer cells.
In APACHE we aim to investigate the fundamentals involved in the lethal effects of cold plasmas on bone cancer cells, and to develop improved bone cancer therapies. To achieve this we will take advantage of the highly reactive species generated by APP in the liquid media, which we will use in an incremental strategy: i) to investigate the effects of APP treated liquid on bone cancer cells, ii) to evaluate the potential of combining APP treated liquid in a hydrogel vehicle with/wo CaP biomaterials and iii) to ascertain the potential three directional interactions between APP reactive species in liquid medium with biomaterials and with chemotherapeutic drugs.
The methodological approach involves an interdisciplinary team, dealing with plasma diagnostics in gas and liquid media; with cell biology and the effects of APP treated with bone tumor cells and its combination with biomaterials and/or with anticancer drugs.
In this first 18 months of the project, we have worked intensely on setting up the laboratory, the equipment, implementation of new experimental protocols, hiring the new research team and, in sum, to set-off the project for proper development.
From the scientific point of view, we have worked in different areas as foreseen in the DoA:
i. A more physic-chemical part related to the characterization of plasma sources and their effects in different liquids,
ii. A part related with biomaterials, where different hydrogels have been developed, and the effects of plasmas therein have been evaluated with regard to the generation of RONS, and
iii. A more biological-oncological area where we have been evaluating the effects of different plasma-treated liquids on a variety of cells.
Therefore, we have totally or partially achieved some of the milestones set up in the project:
- M1 & M2: Characterization of the main species of the plasma jets in different conditions, & Comparison between the characteristics of the different plasma sources employed
Optical emission spectroscopy has been employed to characterize the main species from the gas phase, as well as the rotational and vibrational temperatures of the plasma gas phase, from the 3 different plasma sources. Different conditions of distance and gas flow have been evaluated with the different sources in presence and absence of liquid media during plasma treatment.
- M3, M4: Characterization of main species generated by APP in liquids, cell culture media & with hydrogels
Different liquids (water, saline solutions), cell culture media with different compositions have been treated with plasma
- M6: Synthesis and physic-chemical characterization of biocompatible polymer hydrogels
We have explored the preparation of different biocompatible hydrogels which include alginate, gelatin, combinations of gelatin-alginate, hydroxipropylmethyl cellulose (HPMC), collagen, polyethylene oxide copolymers etc. and others are currently under investigation. One point of interest in the selection of the hydrogels has been the crosslinking method, and we put forward those allowing relatively quick crosslinking.
The gelling / crosslinking conditions for each of them has been investigated by the relevant techniques depending on the kind of crosslinking taking place. Characterisation of the hydrogels by relevant techniques (FTIR, SEM, Rheology) has been performed or is currently ongoing.
- M7: Synthesis & characterization of CaP biomimetic microspheres & their combination with hydrogels
This item is currently ongoing. We are working in two lines: We have synthesized and characterized: a) CaP biomimetic microspheres, as well as b) hydroxyapatite biomimetic nanoparticles, that will be in a second stage incorporated to hydrogels.
- M9: Determination of the stability and lifetime of APP-liquid generated species blended in hydrogels
This has been achieved for some of the hydrogels developed and characterized under plasma treatment up to now, and is under investigation for others.
- M11: Correlation of [ROS & RNS] in liquids and biomaterials with their anticancer potential
This task is also ongoing, as we have been able to correlate the amount of RONS in different liquids (in particular cell culture media and some saline solutions) on their effects on bone cancer cells. As a general rule, higher amounts of RONS are related with bone cell toxicity, and we have already been able to intuit a threshold for toxicity or survival for healthy bone cells, so we’re moving in the right direction to ascertain suitable dose.
- M12: Fundamental description of the lethal effects of APP-treated liquids & vehicles on bone cancer cells
We are currently working on the description of the possible mechanisms involved in the bone anticancer effects shown by plasma jet treated liquids, as observed by alterations in mitochondria, metabolic activity, protein expression etc. The first results obtained in this line are very
It is expected that the project will allow to progress beyond the state of the art in bone osteosarcoma-related therapies, as we have already obtained proof of concept of selective bone anticancer activity from plasma-treated cell culture media. We are currently obtaining similar in vitro results with other liquid vehicles more useful for the clinics, and quickly progressing to 3D tumor models to be able to evaluate situations closer to the real scenario.
The plasma-treated biomaterials we are currently developing and characterizing will allow a further step forward in this sense.
More info: https://ercapache.upc.edu/en.