Periodic Reporting for period 4 - VERDI (polyValent mEsopoRous nanosystem for bone DIseases)
Reporting period: 2021-04-01 to 2022-09-30
Finding simple solutions to complex problems has been a challenge for human kind for decades. VERDI aims at designing a multifunctional nanosystem to heal complex bone diseases: bone infection, bone cancer and osteoporosis. The novelty of this proposal is the design of a nanosystem that may address several diseases using a unique, versatile and scalable strategy. Mesoporous silica nanoparticles (MSNs) are selected as the main component of the nanoplatform because of their biocompatibility, robustness, loading capacity and versatile surface modification. MSNs will be modified by rational selection of building blocks, with targeting and/or therapeutic abilities, to tackle either one or a combination of pathologies. These features will enable us to deliver a library of nanomedicines using a toolbox of building blocks, customizing a specific nanosystem depending on the disease to be treated.
Bone cancer including primary tumors and bone metastases is a major concern, which counts with more than 3.4 million new cases and 1.7 million cancer-related deaths each year in Europe. Moreover, it is present in 70% patients dying of cancer. Bone infection is an inflammatory process caused by an infecting microorganism accompanied by bone destruction. The annual incidence of this disease in Europe has been estimated to be 2/100,000 persons. On the other hand, in a perfect scenario, there should be equilibrium between the rates of bone gain and bone loss. However, disruption of this balance takes place in metabolic bone diseases such as osteoporosis, which is by far the most frequent metabolic disease affecting bone. This pathology is the responsible of more than 9 million fractures annually worldwide. Current treatments for these three diseases are not always effective. We propose tackling both isolated and comorbid bone diseases with a multifunctional platform.
Bone cancer including primary tumors and bone metastases is a major concern, which counts with more than 3.4 million new cases and 1.7 million cancer-related deaths each year in Europe. Moreover, it is present in 70% patients dying of cancer. Bone infection is an inflammatory process caused by an infecting microorganism accompanied by bone destruction. The annual incidence of this disease in Europe has been estimated to be 2/100,000 persons. On the other hand, in a perfect scenario, there should be equilibrium between the rates of bone gain and bone loss. However, disruption of this balance takes place in metabolic bone diseases such as osteoporosis, which is by far the most frequent metabolic disease affecting bone. This pathology is the responsible of more than 9 million fractures annually worldwide. Current treatments for these three diseases are not always effective. We propose tackling both isolated and comorbid bone diseases with a multifunctional platform.
We have been able to create a toolbox based on MSNs with many available tools to adapt this nanoplatform to the individual needs of every patient and disease. Thus, and considering that the General Objective of the VERDI project was Developing a versatile polyvalent system that could be adapted to situations of clinical relevance, we have been able to go a step further in comparison with the previous period, producing the versatile polyvalent system and exploring it as a potential treatment to three different diseases.
Concerning INFECTION treatment, the great versatility of MSNs has allowed us to advance in developing different nanosystems to treat bacterial infection able to overcome the limitations of current treatments. To this aim, five approaches have been addressed, mainly focused in achieving: (i) Deep knowledge on antibiotic released doses from MSNs and their impact on Gram+ and Gram- bacterial biofilms, a pivotal study for future custom-made therapies; (ii) Targeted therapy (to bacterial wall and/or biofilm); (iii) Furtive antibacterial nanosystems able to evade the immune system defence mechanisms; (iv) Combined antimicrobial therapies for improved and/or synergistic antibacterial and/or antibiofilm effects, such as the combination of different antibiotics with different but complementary activity, or antibiotics and antimicrobial metal ions, into a single mesoporous silica carrier; (v) Stimuli-response antibiotic delivery therapies through near infrared light and magnetic external stimulus.
Concerning CANCER treatment, significant achievements were made in developing advanced MSNs-based nanosystems for bone cancer therapy. Different approaches have been conducted, focused on achieving: i) Selectivity towards tumor vascular endothelium or tumor cell membrane of solid tumors, by decorating drug-loaded MSNs with active targeting elements; ii) Zero premature chemotherapeutic cargo release until the target is reached, by developing stimuli-responsive nanosystems that release the drug within the tumor cell once exposed to certain stimuli (pH, redox conditions, magnetic field, light, etc); iii) Deep penetration into dense tumoral masses by using non-pathogenic bacteria as carriers of drug-loaded MSNs, or either anchoring proteolytic enzymes on the MSNs surface to digest the collagen-rich and dense extracellular matrix.
Concerning OSTEOPOROSIS, we have been able to co-deliver two therapeutic agents – SOST siRNA and osteostatin – inside cells using MSNs as nanocarriers. The employed siRNA was selected to silence SOST, which is responsible for the expression of sclerostin, overexpression of which reduces osteoblast formation and differentiation. Thus, silencing SOST with a specific siRNA in osteocytes could represent an effective alternative treatment approach. Additionally, the network of cavities from MSNs allowed loading an osteogenic peptide, osteostatin – a parathyroid hormone–related peptide that has been observed to stimulate osteoblastic cell growth and differentiation. Thanks to the VERDI project, the developed platform was evaluated both in vitro and in vivo, observing that the combination of SOST siRNA with the osteogenic peptide in ovariectomized mice resulted in a synergy – not only knocking down the selected gene, but also increasing the expression of early markers of osteogenic differentiation, and improving the bone microarchitecture.
Concerning INFECTION treatment, the great versatility of MSNs has allowed us to advance in developing different nanosystems to treat bacterial infection able to overcome the limitations of current treatments. To this aim, five approaches have been addressed, mainly focused in achieving: (i) Deep knowledge on antibiotic released doses from MSNs and their impact on Gram+ and Gram- bacterial biofilms, a pivotal study for future custom-made therapies; (ii) Targeted therapy (to bacterial wall and/or biofilm); (iii) Furtive antibacterial nanosystems able to evade the immune system defence mechanisms; (iv) Combined antimicrobial therapies for improved and/or synergistic antibacterial and/or antibiofilm effects, such as the combination of different antibiotics with different but complementary activity, or antibiotics and antimicrobial metal ions, into a single mesoporous silica carrier; (v) Stimuli-response antibiotic delivery therapies through near infrared light and magnetic external stimulus.
Concerning CANCER treatment, significant achievements were made in developing advanced MSNs-based nanosystems for bone cancer therapy. Different approaches have been conducted, focused on achieving: i) Selectivity towards tumor vascular endothelium or tumor cell membrane of solid tumors, by decorating drug-loaded MSNs with active targeting elements; ii) Zero premature chemotherapeutic cargo release until the target is reached, by developing stimuli-responsive nanosystems that release the drug within the tumor cell once exposed to certain stimuli (pH, redox conditions, magnetic field, light, etc); iii) Deep penetration into dense tumoral masses by using non-pathogenic bacteria as carriers of drug-loaded MSNs, or either anchoring proteolytic enzymes on the MSNs surface to digest the collagen-rich and dense extracellular matrix.
Concerning OSTEOPOROSIS, we have been able to co-deliver two therapeutic agents – SOST siRNA and osteostatin – inside cells using MSNs as nanocarriers. The employed siRNA was selected to silence SOST, which is responsible for the expression of sclerostin, overexpression of which reduces osteoblast formation and differentiation. Thus, silencing SOST with a specific siRNA in osteocytes could represent an effective alternative treatment approach. Additionally, the network of cavities from MSNs allowed loading an osteogenic peptide, osteostatin – a parathyroid hormone–related peptide that has been observed to stimulate osteoblastic cell growth and differentiation. Thanks to the VERDI project, the developed platform was evaluated both in vitro and in vivo, observing that the combination of SOST siRNA with the osteogenic peptide in ovariectomized mice resulted in a synergy – not only knocking down the selected gene, but also increasing the expression of early markers of osteogenic differentiation, and improving the bone microarchitecture.
Regarding cancer treatment, there have been reached in vitro and in vivo tests with promising results, which practically covers all the expected work planned at the beginning of the project. Now, we are going a step forward to face the next challenge, to be able to deep inside such preclinical studies, in collaboration with clinicians, to gather more information on the particularities of the different nanocarrier-based treatment of cancer to achieve a possible translation into clinical studies.
In the case of infection treatment, we have developed a wide range of MSNs-based nanomedicines, whose final goal would be addressing custom-made antibacterial therapies. They have been successfully evaluated in vitro and in vivo tests in an infection model in rabbit. They constitute promising alternatives to conventional therapies by increasing the antimicrobial efficiency, decreasing the side effects and preventing the emergence of bacterial resistances.
Regarding potential treatment of osteoporosis, we have developed a technology able to go all the way from the initial design of the platform to the animal model evaluation where the effectiveness of a new potential osteoporosis treatment based on MSNs was evaluated. The nanosystem here produced was based on funcionalized MSNs loaded with a siRNA to silence the gen SOST responsible to produce sclerostin, that is overexpressed in osteoporotic situations. Additionally, the porous network was loaded with an anabolic agent (osteostatin) to fuel the production of new bone tissue in the eventual osteoporotic scenario. The system was evaluated both in vitro and in vivo in different cellular and animal models showing a remarkable remission of osteoporosis with an improvement in bone microarchitecture.
In the case of infection treatment, we have developed a wide range of MSNs-based nanomedicines, whose final goal would be addressing custom-made antibacterial therapies. They have been successfully evaluated in vitro and in vivo tests in an infection model in rabbit. They constitute promising alternatives to conventional therapies by increasing the antimicrobial efficiency, decreasing the side effects and preventing the emergence of bacterial resistances.
Regarding potential treatment of osteoporosis, we have developed a technology able to go all the way from the initial design of the platform to the animal model evaluation where the effectiveness of a new potential osteoporosis treatment based on MSNs was evaluated. The nanosystem here produced was based on funcionalized MSNs loaded with a siRNA to silence the gen SOST responsible to produce sclerostin, that is overexpressed in osteoporotic situations. Additionally, the porous network was loaded with an anabolic agent (osteostatin) to fuel the production of new bone tissue in the eventual osteoporotic scenario. The system was evaluated both in vitro and in vivo in different cellular and animal models showing a remarkable remission of osteoporosis with an improvement in bone microarchitecture.