An observational study in Cytotoxicity, sponsored by Stefano Zaffagnini. Not yet recruiting at 1 site in Italy. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-08-04.
Sponsored by Stefano Zaffagnini · Observational
The anterior cruciate ligament (ACL) is the primary stabilizer of the knee joint, and ACL injuries are highly prevalent, particularly among physically active and athletic individuals. Although ACL reconstruction is a well-established orthopedic procedure, significant challenges remain regarding biological integration between the graft and bone, which may negatively affect clinical outcomes.
In recent years, advanced biomaterials and regenerative medicine approaches have gained increasing attention as potential strategies to enhance osteointegration and promote more physiological tissue healing. Before clinical application, these materials must undergo rigorous in vitro biological evaluation in accordance with international standards, particularly ISO 10993-5 for cytotoxicity assessment.
The study will investigate cytotoxicity, cell viability, inflammatory responses, pro-fibrotic effects, and osteogenic potential using relevant human cell models. The regenerative effects of platelet-rich plasma (PRP), a source of growth factors, will also be evaluated.
The biomaterials under investigation include a titanium alloy and polylactic acid (PLA), both widely used in orthopedic applications. The main objective is to demonstrate their biocompatibility, absence of cytotoxic, inflammatory, and pro-fibrotic effects, and their ability to support osteogenic processes and tissue integration. The findings will provide essential evidence for subsequent preclinical in vivo studies and future clinical translation.
Stefano Zaffagnini is the lead sponsor of 13 studies on the registry; 10 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Subjects will be recruited among patients admitted to the IRCCS Istituto Ortopedico Rizzoli and scheduled for total knee arthroplasty for the treatment of chondral defects and/or undergoing regenerative infiltrative therapies with BMC and PRP.
For the study, biological material obtained during the surgical removal of femoral condyles, tibial plateaus and synovial membranes, as well as during implantation of the prosthetic components, will be used. For BMC and PRP, only waste material not required for the surgical procedures will be collected.
The recovery of such material will be performed during routine clinical practice by the medical staff of the Orthopaedic and Trauma Clinic II.
Femoral condyle, tibial plateau and synovial membrane samples
Patients undergoing primary total knee arthroplasty at the Orthopaedic and Trauma Clinic II of the IRCCS Istituto Ortopedico Rizzoli (Bologna, Italy), in whom collection of tibial plateau, femoral condyles and/or synovial tissue is planned.
Inclusion criteria:
Age 18-80 years, male or female Primary tricompartmental osteoarthritis (BMI) \< 35 Kellgren-Lawrence grade III-IV osteoarthritis Written
Exclusion criteria:
Previous partial knee arthroplasty or cartilage repair/regenerative procedures Rheumatoid arthritis or chronic / therapy Positive testing for , or infection Concentrated bone marrow (BMC) samples
Patients of both sexes providing written informed consent and presenting with the following characteristics:
Inclusion criteria:
Age 18-70 years Medial compartment knee osteoarthritis (Kellgren-Lawrence grade II-III for >4 months) Failure of ≥6 months of conservative treatment (NSAIDs/analgesics, hyaluronic acid, corticosteroid or PRP injections) Written informed consent
Exclusion criteria:
Inability to provide informed consent Knee trauma within the previous 6 months , rheumatic disease, uncontrolled diabetes, uncontrolled thyroid disorders Alcohol or drug abuse BMI > 35 Intra-articular injections within the previous 6 months Knee surgery within the previous 12 months HIV, HBV or HCV positivity -rich plasma (PRP) samples
Patients of both sexes with degenerative cartilage disease of the knee.
Inclusion criteria:
Age 18-65 years Clinical signs and symptoms of knee cartilage degeneration Radiographic or MRI evidence of degeneration (Kellgren-Lawrence grade II-IV) > 11 g/dL Platelet count > 150,000/mm³ No abnormalities Written informed consent
Exclusion criteria:
Rheumatoid arthritis or chronic corticosteroid/immunosuppressive therapy Uncontrolled diabetes Hematological disorders or anticoagulant/antiplatelet therapy Thyroid metabolic disorders Alcohol, drug or medication abuse NSAID use within 3 days prior to blood draw Cardiovascular disease contraindicating a 150 mL blood draw HIV, HBV or HCV positivity
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Subjects eligible among patients scheduled for primary total knee arthroplasty, in whom harvesting of the tibial plateau and/or femoral condyles and/or synovial tissue is planned
Concentrated bone marrow samples
Platelet-rich plasma samples
Cellular health parameters
Cellular health parameters were assessed after 72 hours of exposure to the materials and compared with standardized control samples
Time frame: 72 hours
Pro-inflammatory cytokines
Levels of pro-inflammatory cytokines were measured after 6, 24 and 48 hours of exposure to the materials
Time frame: 48 hours
ROS
Markers of oxidative stress were evaluated after 72 hours of exposure to the materials
Time frame: 48 hours
Osteogenic potential
Osteogenic potential was assessed by evaluating the gene expression of specific osteogenic markers and the production of protein biomarkers (ALP and P1NP) at 7, 14, and 28 days
Time frame: 28 days
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
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Stefano Zaffagnini