Biomedical subjects

Roberto Giardino

Publications and source records attributed to Roberto Giardino.

At least 19 recordsLinked to original sources

PubMed2006

Nanocomposites of hydroxyapatite with aspartic acid and glutamic acid and their interaction with osteoblast-like cells.

The direct synthesis of hydroxyapatite (HA)-aspartic acid (ASP) and HA-glutamic acid (GLU) nanocrystals was carried out in presence of different amounts of the amino acids in solution. ASP and GLU incorporation into HA crystals reduces the coherent length of the perfect crystalline domains along the long dimension (002) and, even more, along the cross section (310) of the apatite crystals, suggesting a specific interaction of the amino acids with the HA structure. FTIR analysis indicates that the carboxylic groups of the acidic amino acids interact with the calcium ions of HA. The relative amount of ASP incorporation into HA nanocrystals is greater than that of GLU, suggesting a greater affinity of ASP for HA. Osteoblast-like, MG63, cells cultured on the composite nanocrystals display good proliferation and increased values of ALP activity, collagen type I, TGF-betaI and osteocalcin production, indicating that the presence of the acidic amino acids enhances osteoblast activation and extra-cellular matrix mineralization processes.

Aspartic Acid↗

PubMed2005

Transplantation of chondrocytes seeded on collagen-based scaffold in cartilage defects in rabbits.

Recent success in tissue engineering by restoring cartilage defects by transplanting autologous chondrocyte cells on a three-dimensional scaffold has prompted the improvement of this therapeutic strategy. Here we describe a new approach investigating the healing of rabbit cartilage by means of autologous chondrocytes seeded on a biomaterial made of an equine collagen type I-based scaffold. Full-thickness defects were created bilaterally in the weight-bearing surface of the medial femoral condyle of both femora of New Zealand male rabbits. The wounds were then repaired by using both chondrocytes seeded on the biomaterial and biomaterial alone. Controls were similarly treated but received either no treatment or implants of the delivery substance. Histological examination of the reconstructed tissues at 1, 3, 6, and 12 months after transplantation showed that at 1 and 3 months there was no formation of reconstructed tissue in any of the groups evaluated; after 6 months there was evidence of a newly regenerated tissue with some fibrocartilaginous features only in the group treated with biomaterial-seeded cells, and at 12 months a more organized tissue was evident in the same group. With regards to the group transplanted with biomaterial alone and the untreated control group, there was no evidence of new tissue production. These results advocate the use of this collagen-based scaffold for further in vivo studies on large size animals and, finally, in human clinical trials for the treatment of knee cartilage defects.

Animals↗

PubMed2005

Hyaluronic acid hydrogel added with ibuprofen-lysine for the local treatment of chondral lesions in the knee: in vitro and in vivo investigations.

The effect of hyaluronan-based hydrogel with a cross-linking degree of 50% (i.e., the amount of carboxylate groups involved in the cross-lining reaction) (Hyal 50%), loaded with an anti-inflammatory drug (ibuprofen-lysine) for local administration in the osteoarthritic knee was evaluated. The kinetic of drug release from Hyal 50% hydrogel was performed in vitro by a continuous flow system. The release was studied at three different rates (0.375, 0.073, and 0.005 mL/s), and for the slowest one a period of 8 days was necessary to receive the complete release of the drug. A chondral defect was caused in the right femoral medial condyle of 24 rabbits. Twelve animals were treated with Hyal 50%+ibuprofen-lysine and 12 with Hyal 50% by percutaneous injection. The treatments were repeated every 10 days, for three or five times. At 30 and 50 days, no significant differences were observed between the groups (mean score at 30 days: 4.4+/-0.6 in Hyal 50%-treated group and 5.1+/-0.7 in Hyal 50% +Ibuprofen-lysine-treated group; mean score at 50 days: 6.9+/-0.6 in Hyal 50%-treated group and 7.1+/-0.6 in Hyal 50%+ Ibuprofen-lysine-treated group). A significant difference was observed in bone mineral density of the total tibia of rabbits treated by Hyal 50% + Ibuprofen-lysine in comparison with those treated only by Hyal 50%. The positive effects of Hyal 50% on chondral lesions were maintained in the presence of ibuprofen-lysine with the adjunctive effect of an increased limb usage, most likely due to less pain and discomfort.

Animals↗

PubMed2005

Physical characterization of different-roughness titanium surfaces, with and without hydroxyapatite coating, and their effect on human osteoblast-like cells.

The aim of this study was to characterize and compare various titanium (Ti) and hydroxyapatite (HA) coatings on Ti6Al4V, in view of their application on noncemented orthopedic implants. Two innovative vacuum plasma sprayed (VPS) coatings, the first of ultrahigh rough and dense Ti (PG60, Ra=74 microm) and the second of ultrahigh rough and dense Ti coated with HA (HPG60, Ra=52 microm), have been developed, and the response of osteoblast-like cells (MG-63) seeded on these new coatings was evaluated in comparison to: a low roughness and sandblasted (Ti/SA, Ra=4 microm) Ti6Al4V surface; Ti medium (TI01, Ra=18 microm), and high (TI60, Ra=40 microm) roughness VPS coatings; and the relative Ti plus HA duplex coatings (HT01, Ra=12 microm and HT60, Ra=36 microm respectively), also obtained by VPS. PG60 coating presented no open porosity, making it dense and potentially intrinsically stronger. Cell adhesion and proliferation on PG60 was similar to those of the smoothest one (Ti/SA) and adhesion on ultrahigh roughness was lower than the medium- and high-roughness coatings, whereas cell proliferation on PG60 was lower than TI60. The HA coating determined significant increases in cell proliferation at medium and high roughness levels when compared to the relative Ti coating, but not compared to the ultrahigh one; all HA-coated surfaces showed a decrease in alkaline phosphatase activity and collagen I production. Surface morphology and the HA coating strongly affected cell behavior. However, ultrahigh values of roughness are not correctly seen by cells, and the presence of HA has no improving effects.

Biocompatible Materials↗

PubMed2005

Physical and biological characterizations of a novel multiphase anodic spark deposition coating to enhance implant osseointegration.

The present study assessed in vitro the short-term cellular response to surface physico-chemical properties of a new, purposed bioactive surface treatment called BioSpark performed on simply machined and on sand-blasted titanium. Material characterisation was carried out using scanning electron microscopy, energy dispersion spectroscopy, laser profilometry, and thin film X-ray diffraction. The in vitro biological study showed a suitable cellular response with adhesion and spreading level comparable for all the tested specimens. The proliferation analysis demonstrated that all the surfaces successfully supported cellular colonisation; in particular, higher cellular proliferation activity was observed on the BioSpark-treated materials, with values higher than machined titanium. The results suggest that the BioSpark treatment represents a smart way to enhance osteoblastic cellular colonisation and thus improve osteointegration processes of machined and sandblasted titanium for orthopaedic and dental implants.

Bone and Bones↗

PubMed2005

The in vivo behaviour of a sol-gel glass and a glass-ceramic during critical diaphyseal bone defects healing.

The in vivo evaluation, in New Zealand rabbits, of a sol-gel glass 70% CaO-30% SiO2 (in mol%) and a glass-ceramic obtained from thermal treatment of the glass, both bioactive in Kokubo's simulated body fluid (SBF), is presented. Femoral bone diaphyseal critical defects were filled with: (i) sol-gel glass cylinders, (ii) glass-ceramic cylinders, or (iii) no material (control group). Osteosynthesis was done by means of anterior screwed plates with an associate intramedullar Kirschner wire. Each group included 10 mature rabbits, 9 months old. Follow-up was 6 months. After sacrifice, macroscopic study showed healing of bone defects, with bone coating over the cylinders, but without evidence of satisfactory repair in control group. Radiographic study showed good implant stability and periosteal growth and bone remodelling around and over the filled bone defect. The morphometric study showed minimum evidences of degradation or resorption in glass-ceramic cylinders, maintaining its original shape, but sol-gel glass cylinders showed abundant fragmentation and surface resorption. An intimate union of the new-formed bone to both materials was observed. Mechanical study showed the higher results in the glass-ceramic group, whereas sol-gel glass and control group showed no differences. The minimum degradation of glass-ceramic cylinders suggests their application in critical bone defects locations of transmission forces or load bearing. The performance of sol-gel glass cylinders suggests their usefulness in locations where a quick resorption should be preferable, considering the possibility of serving as drug or cells vehicle for both of them.

Animals↗

PubMed2005

Comparative in vitro study on a ultra-high roughness and dense titanium coating.

A new implant surface has been developed with the purpose of avoiding as much stress shielding as possible, and thus prolong the prosthesis lifespan. The aim of this study was to investigate the in vitro effect of this new ultra-high roughness and dense Titanium (Ti) surface (PG60, Ra = 74 microm) in comparison with medium (TI01, Ra = 18 microm) and high (TI60, Ra = 40 microm) roughness and open porous coatings; all the coatings were obtained by vacuum plasma spraying. MG63 osteoblast-like cells were seeded on the tested materials and polystyrene, as control, for 3 and 7 days. Cells proliferated on the material surfaces similarly to the control. Alkaline phosphatase activity had lower values for TI60 than TI01 (p < 0.0005) and PG60 (p < 0.005). Osteocalcin levels measured on TI60 were significantly (p < 0.0005) lower in comparison with TI01 and PG60 at 7 days. Procollagen-I synthesis reduced with increasing roughness and the lowest data was found for PG60. While at 3 days Transforming Growth Factor beta1 levels augmented with increasing roughness, at 7 days TI60, the high roughness surface, was significantly lower than PG60 (p < 0.005) and TI01 (p < 0.001). All tested materials showed significantly higher Interleukin-6 levels than those of polystyrene at both experimental times. Nitric Oxide activity on TI01 was significantly (p < 0.05) higher than on TI60 and polystyrene. In conclusion, the new ultra-high roughness and dense coating PG60 provided a good biological response, even though, at least in vitro, it behaved similarly to the coatings already used in orthopaedics.

Alloys↗

PubMed2005

Proliferative and re-defferentiative effects of photo-immobilized micro-patterned hyaluronan surfaces on chondrocyte cells.

A photo-immobilisation procedure was utilised to create two different micro-patterned surfaces (tracks 25 and 5 microm wide) of hyaluronan (Hyal) on polyethylene-terephthalate (PET) previously plasma activated. Aim of the study was to investigate the proliferation and re-differentiation capacity of articular chondrocytes cultured on micro-patterned Hyal, compared to homogeneous Hyal and plain plasma-treated (pt-)PET substrates. Cytotoxicity, cell proliferation, activation and differentiation of articular knee cartilage chondrocytes (Mongrel sheep) were evaluated after 14 days of culture. It was found that micro-patterned Hyal surfaces induced the adhesion, migration and alignment of chondrocytes, as shown by light and scanning electron microscopy. Furthermore, the same surfaces induced chondrocyte differentiation, with a significant increase of aggrecan and collagen type II production, while homogeneous Hyal and pt-PET surfaces did not.

Aggrecans↗

PubMed2005

In vivo experimental study on bone regeneration in critical bone defects using an injectable biodegradable PLA/PGA copolymer.

OBJECTIVES: An assessment was done of the bone-healing rate after implantation of a polylactide/polyglycolide copolymer (PLA-PGA) 50/50 dispersed in aqueous solution of PGA and dextran, used as bone substitutes in an animal model. STUDY DESIGN: Two groups of 5 rabbits each were used. In both the femoral condyles, a critical size defect of 6x10 mm was made. On the right side PLA/PGA was inserted; the left side remained empty. Thirty and 90 days after surgery the animals were killed. RESULTS: Defects left unfilled showed no spontaneous healing after 30 and 90 days. Sites filled with experimental materials showed new bone ranging between 11.46% and 76.82% after 30 days, and 75.98% and 95.34% after 90 days. Histomorphometry showed an increase in bone maturation between day 30 and 90 in experimental sites. At day 90, no statistical difference was seen as compared to normal bone. CONCLUSION: PLA/PGA copolymer dispersed in hydrosoluble matrix seems to be suitable as osteoconductive material in critical size defects.

Absorbable Implants↗

PubMed2005

Tissue healing in implants immediately placed into postextraction sockets: a pilot study in a mini-pig model.

OBJECTIVE: A pilot in vivo study was conducted to evaluate (1) the rate of osseointegration at apical, middle, and coronal levels of oral implants immediately installed into fresh extraction sockets; (2) the maturation of the newly formed bone surrounding implants during 60 days of healing; and (3) the epithelium seal development. STUDY DESIGN: The premolars of 8 male adult mini-pigs were extracted at each mandibular site under general anesthesia. In the experimental side, Frialit-2 implants were immediately inserted. The gap between bone and implants ranged between 3 and 6 mm circumferencially. Bone specimens were obtained at 7, 15, 30, and 60 days after surgery for histologic and histomorphometric studies. Bone-to-implant contact (BIC), bone volume, trabecular thickness, number, and separation were recorded. Nonparametric exact tests were used to evaluate data. RESULTS: BIC at the coronal level was observed close to 0% at day 7 and increased up to 60% at day 60 after surgery on an average. BIC increased from 11.7% to 47.38% at middle level and from 53.4% to 67.38% at apical level from day 7 to day 60. With respect to bone maturation, in the earlier stages of healing, many thin trabeculae were observed, which, particularly at coronal level, became significantly fewer and thicker in more advanced stages. At day 60, the features of the bone were similar to those of baseline. The epithelium never migrated more than 1.8 mm apically to the top of the alveolar bone level. CONCLUSION: When implants are placed immediately into fresh extraction sockets, in minipig models osseointegration also occurs without initial bone contact.

Analysis of Variance↗

PubMed2005

Stromal stem cells and platelet-rich plasma improve bone allograft integration.

Early vascular invasion is a key factor in bone allograft incorporation. It may reduce the complications related to slow and incomplete bone integration. Bone-marrow-derived stromal stem cells associated with platelet-rich plasma are potent angiogenic inducers proven to release vascular endothelial growth factor. Our goal was to test whether the combination of stromal stem cells and platelet-rich plasma is able to increase massive allograft integration in a large animal model with sacrifice at 4 months. A critical defect was made in the mid-diaphysis of the metatarsal bone of 10 sheep; the study group received an allograft plus stromal stem cells, platelet-rich plasma, and collagen (six animals) and the control group received only the allograft (four animals). Investigation was done with radiographs, mechanical tests and histomorphometric analysis, including new vascularization. Results showed substantial new bone formation in the allograft of the study group. Bone formation is correlated with better vascular invasion and remodeling of the graft in the study group. These results confirm the key role played by stromal stem cells and platelet-rich plasma in bone repair. Further studies are needed to better define the role stromal stem cells play when implanted alone.

Animals↗

PubMed2004

Histomorphometric, ultrastructural and microhardness evaluation of the osseointegration of a nanostructured titanium oxide coating by metal-organic chemical vapour deposition: an in vivo study.

Over the past decade the increase of elderly population has determined a rise in the incidence of bone fractures, and the improvement of the implant-bone interface remains an open problem. Metal-organic chemical vapour deposition (MOCVD) has recently been proposed as a technique to coat orthopaedic and dental prostheses with metal nanostructured oxide films either through the decomposition of oxygenated compounds (single-source precursors) or the reaction of oxygen-free metal compounds with oxygenating agents. The present study was performed to assess the in vivo biocompatibility of commercially pure Ti (control material: TI/MA) implants ( psi 2 mm x 5 mm length) coated with nanostructured TiO2 films by MOCVD (Ti/MOCVD) and then inserted into rabbit femoral cortical (middhiaphysis) and cancellous (distal epiphysis) bone. Histomorphometric, ultrastructural and microhardness investigations were carried out. Four and 12 weeks after surgery, significant (p<0.0005) increases in AI of Ti/MOCVD implants were observed as compared to Ti/MA implants (distal femoral epiphysis: 4 weeks=8.2%, ns; 12 weeks=52.3%, p <0.005; femoral diaphysis: 4 weeks=20.2%, p <0.0005; 12 weeks=10.7%, p <0.005). Bone microhardness results showed significant increases for the Ti/MOCVD versus Ti/MA implants at 200 microm in the femoral diaphysis (4 weeks=14.2, p <0.005) and distal femoral epiphysis (12 weeks=14.5, p <0.01) at 4 and 12 weeks, respectively. In conclusion, the current findings demonstrate that the nanostructured TiO2 coating positively affects the osseointegration rate of commercially pure Ti implants and the bone mineralization at the bone-biomaterial interface in both cortical and cancellous bone.

Animals↗

PubMed2004

Medical grade calcium sulfate hemihydrate in healing of human extraction sockets: clinical and histological observations at 3 months.

BACKGROUND: Following tooth extraction, remodeling and resorption of the alveolar bone at the extraction site characterize wound healing. This produces a reduction in ridge volume and difficulties in delayed placement of implants in an ideal position. Medical grade calcium sulfate hemihydrate (MGCSH) has been proposed as a graft material in extraction sockets to minimize the reduction in ridge volume. The aim of the present study was to investigate the influence of MGCSH on the histopathologic pattern of intrasocket regenerated bone and to evaluate histologically the healed MGCSH grafted extraction socket site 3 months postextraction METHODS: MGCSH was grafted in 10 fresh human extraction sockets in 10 patients. Five post-extraction sockets were used as controls. At 3 months a cylindrical tissue specimen, 2.5 mm in diameter, was trephined from the previously grafted site followed by implant placement. Non-decalcified specimens were sectioned at a cross-horizontal plane and stained with fast green, toluidine blue, and Van Kossa stains for histological and histomorphometrical examination. RESULTS: Histologically, MGCSH was not observed in most of the specimens. Newly formed bone with lamellar arrangements was identified in all the horizontal sections with no difference between apical, medium, and coronal areas. The mean trabecular area in the coronal sections was 58.6% +/- 9.2%; in the medium sections, 58.1% +/- 6.2%; and in the apical sections, 58.3% +/- 7.8%. The differences were not statistically significant. CONCLUSION: MGCSH seems to be an ideal graft material in extraction socket bone regeneration because it is almost completely resorbable, and it allows a new trabecular bone arrangement at 3 months.

Adult↗

PubMed2003

Mechanical and histomorphometric evaluations of titanium implants with different surface treatments inserted in sheep cortical bone.

Improvement of the implant-bone interface is still an open problem and the interest in chemical modification of implant surfaces for cementless fixation has grown steadily over the past decade. Mechanical and histomorphometric investigations were performed at different times on implants inserted into sheep femoral cortical bone to compare the in vivo osseointegration of titanium screws ( X 3.5 x 7 mm length) with different surface treatments. After 8 weeks of implantation, the push-out force of anodized and hydrothermally treated implants (ANODIC) was significantly higher than that of machined implants (MACH) (36%, p<0.0005), whereas a decrease of 39% was observed for acid-etched implants (HF) when compared to other surface treatments. After 12 weeks of implantation, the push-out force values of HF implants were still significantly lower than those observed for MACH (-19%, p<0.01) and hydroxyapatite vacuum plasma-sprayed implants (HAVPS, -25%, p<0.0005), and the highest push-out force was found in HAVPS (p<0.001) implants. After 8 and 12 weeks of implantation, the AI of HF implants was significantly (p<0.05) lower ( approximately -25%) than that of MACH, HAVPS and ANODIC implants. In conclusion, results appear to confirm that there are no specific differences between ANODIC and HAVPS implants in terms of behavior. Moreover, although MACH implants show some surface contaminating agents, they appear to ensure good osseointegration within 12 weeks both mechanically and histomorphometrically, as do ANODIC and HAVPS implants. However, further studies are required to investigate bone hardness and mineralization around implants.

Animals↗

PubMed2003

Platelet-derived growth factors enhance proliferation of human stromal stem cells.

Studies on new procedures for bone reconstruction suggest that autologous cells seeded on a resorbable scaffold can improve the treatment of bone defects. It is important to develop culture conditions for ex vivo expansion of stromal stem cells (SSC) that do not compromise their self-renewing and differentiation capability. Bone marrow SSC and platelet gel (PG) obtained by platelet-rich plasma provide an invaluable source for autologous progenitor cells and growth factors for bone reconstruction. In this study the effect of platelet-rich plasma (PRP) released by PG on SSC proliferation and differentiation was investigated. MTT assay was used to investigate the effect of PRP on proliferation: results showed that PRP induced SSC proliferation. The effect was dose dependent and 10% PRP is sufficient to induce a marked cell proliferation. Untreated cells served as controls. Upon treatment with 10% PRP, cells entered logarithmic growth. Removal of PRP restored the characteristic proliferation rate. Because SSC can gradually lose their capability to differentiate along the chondrogenic and osteogenic lineage during subculture in vitro, we tested whether 10% PRP treatment affected SSC ability to mineralize. SSC were first exposed to 10% PRP for five passages, at passage 6 PRP was washed away and plated cells were treated with dexamethasone (DEX). DEX induced a three-fold increase in the number of alkaline phosphatase positive cells and induced mineralization that is consistent with the differentiation of osteochondroprogenitor cells. In conclusion, 10% PRP promotes SSC proliferation; cells expanded with 10% PRP can mineralize the extracellular matrix once PRP is withdrawn.

Adolescent↗

PubMed2003

Surgical repair of the rotator cuff: a biomechanical evaluation of different tendon grasping and bone suture fixation techniques.

OBJECTIVE: This study investigated the initial strength and failure mode of different rotator cuff repair techniques. BACKGROUND: Full or partial re-rupture of the repair is one of the main post-operative complications for rotator cuff repair. The rate of failure is strongly affected by the extension of the tear, increasing in case of large or massive tears up to 62%. DESIGN: The study was planned to assess the three individual components of the tendon-to-bone repair (tendon grasping, suture knotting, suture-to-bone fixation) and to identify the best combinations in terms of mechanical strength to failure. The best combinations were tested to compare the mechanical behaviour of the entire repair and suggest potential improvements in the repair technique. METHODS: Experimental tests were performed using sheep shoulders. Three tendon-grasping techniques, two suture knotting techniques, and the effect of bone augmentation with metallic plate and bone quality on suture-to-bone fixation were investigated. RESULTS: This study assessed the mechanical behaviour of different repair components. The best combinations of the investigated techniques showed that the weakest link was the tendon-suture interface. More importantly, the compliance of the investigated repairs was large. CONCLUSIONS: The initial strength of the rotator cuff repair can be improved by changing the repair technique. Nevertheless, even a low physiological load stressing the repaired tendon may cause a gap formation at the tendon-bone interface without necessarily producing failure of the repair. RELEVANCE: Post-operative protection of the repaired rotator cuff from tension load is necessary to reduce the risk of delaying or preventing of the healing process.

Animals↗

PubMed2003

Osseointegration of endosseous ceramic implants after postoperative low-power laser stimulation: an in vivo comparative study.

Stimulation with low-power laser (LPL) can enhance bone repair as reported in experimental studies on bone defects and fracture healing. Little data exist concerning the use of LPL postoperative stimulation to improve osseointegration of endosseous implants in orthopaedic and dental surgery. An in vivo model was used for the present study to evaluate whether Ga-Al-As (780 nm) LPL stimulation can improve biomaterial osseointegration. After drilling holes, cylindrical implants of hydroxyapatite (HA) were placed into both distal femurs of 12 rabbits. From postoperative day 1 and for 5 consecutive days, the left femurs of all rabbits were submitted to LPL treatment (LPL group) with the following parameters: 300 J/cm2, 1 W, 300 Hz, pulsating emission, 10 min. The right femurs were sham-treated (control group). Three and 6 weeks after implantation, histomorphometric and microhardness measurements were taken. A higher affinity index was observed at the HA-bone interface in the LPL group at 3 (P<0.0005) and 6 weeks (P<0.001); a significant difference in bone microhardness was seen in the LPL group vs. the control group (P<0.01). These results suggest that LPL postoperative treatment enhances the bone-implant interface.

Aluminum↗

PubMed2003

Human osteopenic bone-derived osteoblasts: essential amino acids treatment effects.

The development of in vitro cell culture methods has made it possible to study bone cell metabolism and growth and obtain a deeper insight into the pathophysiology of common orthopedic diseases such as osteoporosis. After analyzing the effect of two essential amino acids, L-arginine (Arg) and L-lysine (Lys), in previous in vitro and in vivo studies, the present authors investigated the administration of Arg and Lys in osteoblasts derived from human osteopenic bone. After isolation, osteoblasts were cultured in DMEM supplemented with either Arg (0.625 mg/ml/day, Arg Group) or Lys (0.587 mg/ml/day, Lys Group), or both of them (Arg-Lys Group), whereas the Control Group was sham-treated. After 7 days the following parameters were tested in all groups: MTT proliferation test, Alkaline Phosphatase (ALP), Nitric Oxide (NO), Calcium (Ca), Phosphorus (P), Osteocalcin (OC), C-Terminal Procollagen type I (PICP), Interleukin-6 (IL-6), Transforming Growth Factor-beta 1 (TGF-beta 1), Platelet Derived Growth Factor (PDGF) and Insulin-Like Growth Factor-I (IGF-I). Results were compared with those obtained from human healthy bone to verify the effect of the amino acids on osteoblasts derived from pathological tissue. In addition, a comparison was also made with the results obtained from rat osteopenic bone to assess reliability of the in vitro model. The current results support previous findings and indicate that Arg and Lys stimulation has a positive effect on osteoblast proliferation, activation and differentiation. Therefore, administration of these amino acids may be useful in clinical treatment and prevention of osteoporosis.

Aged↗