Osteogenic differentiation of CD271(+) cells from rabbit bone marrow cultured on three phase PCL/TZ-HA bioactive scaffolds: comparative study with mesenchymal stem cells (MSCs).

Tissue engineering is one of the major challenges of orthopedics and trauma surgery for bone regeneration. Biomaterials filled with mesenchymal stem cells (MSCs) are considered the most promising approach in bone tissue engineering. Furthermore, our previous study showed that the multi-phase poly [ε-caprolactone]/thermoplastic zein-hydroxyapatite (PCL/TZ-HA) biomaterials improved rabbit (r) MSCs adhesion and osteoblast differentiation, thus demonstrating high potential of this bioengineered scaffold for bone regeneration. In the recent past, CD271 has been applied as a specific selective marker for the enrichment of MSCs from bone marrow (BM-MSCs). In the present study, we aimed at establishing whether CD271-based enrichment could be an efficient method for the selection of rBM-MSCs, displaying higher ability in osteogenic differentiation than non-selected rBM-MSCs in an in vitro system. CD271(+) cells were isolated from rabbit bone marrow and were compared with rMSCs in their proliferation rate and osteogenic differentiation capability. Furthermore, rCD271(+) cells were tested in their ability to adhere, proliferate and differentiate into osteogenic lineage, while growing on PCL/TZ-HA scaffolds, in comparison to rMSCs. Our result demonstrate that rCD271(+) cells were able to adhere, proliferate and differentiate into osteoblasts when cultured on PCL/TZ-HA scaffolds in significantly higher levels as compared to rMSCs. Based on these findings, CD271 marker might serve as an optimal alternative MSCs selection method for the potential preclinical and clinical application of these cells in bone tissue regeneration.

Design of novel three-phase PCL/TZ-HA biomaterials for use in bone regeneration applications.

The design of bioactive scaffold materials able to guide cellular processes involved in new-tissue genesis is key determinant in bone tissue engineering. The aim of this study was the design and characterization of novel multi-phase biomaterials to be processed for the fabrication of 3D porous scaffolds able to provide a temporary biocompatible substrate for mesenchymal stem cells (MSCs) adhesion, proliferation and osteogenic differentiation. The biomaterials were prepared by blending poly(epsilon-caprolactone) (PCL) with thermoplastic zein (TZ), a thermoplastic material obtained by de novo thermoplasticization of zein. Furthermore, to bioactivate the scaffolds, microparticles of osteoconductive hydroxyapatite (HA) were dispersed within the organic phases. Results demonstrated that materials and formulations strongly affected the micro-structural properties and hydrophilicity of the scaffolds and, therefore, had a pivotal role in guiding cell/scaffold interaction. In particular, if compared to neat PCL, PCL-HA composite and PCL/TZ blend, the three-phase PCL/TZ-HA showed improved MSCs adhesion, proliferation and osteogenic differentiation capability, thus demonstrating potential for bone regeneration.

Osteogenesis induced by autologous bone marrow cells transplant in the pediatric skull.

BACKGROUND AND PURPOSE: The ability of cranial bone to repair defects of continuity is limited and it is mostly dependent on the age of the patient. In infancy and in early pediatric age, the scarce thickness of the calvarial bones and the need for a harmonic development of the child's skull limit the application of most of the surgical procedures usually utilized in older patients. We tested the ability of mononucleated cells, derived from the patient's bone marrow and transplanted on the site of the cranial bone defect, to increase the rate of mineralization of the autologous osteogenesis to obtain the complete restoration of the skull continuity. METHOD: Four children, aged 26, 28, 37, and 79 months, respectively, affected by a stabilized and persistent cranial bone defect of posttraumatic or postsurgical origin, were treated. A sandwich-shaped shell, made of extrused absorbable polylactic copolymers material, was used to hold in place a freeze-dried mineralized collagen matrix associated with a nonceramic hydroxyapatite scaffold, where autologous bone marrow mononucleated cells were inseminated. RESULTS: In all patients, a rapid autologous bone osteogenesis was observed with a clear dimensional reduction of the bone defect few months after the autologous bone marrow cells seeding. CONCLUSIONS: The preliminary results of this research suggest the use of autologous bone marrow cells to increase the autologous osteogenesis in early pediatric age in cases in which correction of skull bone defects is best realized with autologous bone.

Sevoflurane-remifentanil vs isoflurane-remifentanil for the surgical correction of craniosynostosis in infants.

BACKGROUND: The aim of the present study was to compare the efficacy of isoflurane-remifentanil and sevoflurane-remifentanil combinations during neurosurgical correction craniosynostosis. METHODS: Twenty-two infants with craniosynostosis received a slow bolus of remifentanil followed by continuous infusion. The infants were randomly divided into two groups: remifentanil followed by sevoflurane (the 'sevoflurane group'), and remifentanil followed by isoflurane (the 'isoflurane group'). We monitored electrocardiogram (ECG), heart rate (HR), invasive arterial blood pressure (IABP), pulse oximetry saturation (SpO(2)), endtidal CO(2) (P(ECO(2))), inspired fraction of oxygen (FiO(2)) and endtidal volatile agent (PE volatile agent) at 12 time points, from the beginning of surgery (T0) until the cessation of drugs (T11). The volatile agent was stopped prior to skin suture and the remifentanil infusion after skin closure. Subsequently, we evaluated recovery time of spontaneous breathing and spontaneous eye opening and time of extubation at 5, 10, and 15 min after extubation, the Steward Recovery Score (SRS) was assessed. Patients were then transferred to the Pediatric Intensive Care Unit (PICU). RESULTS: During the surgical procedure the hemodynamic parameters between the two groups did not show statistically significant differences. There were also no significant differences in terms of awakening time or SRS. CONCLUSIONS: The rapid recovery of the children (confirmed by their high values of SRS) makes it possible to reliably assess the patient's neurological condition immediately after surgery.

Prolonged intracranial pressure (ICP) monitoring in non-traumatic pediatric neurosurgical diseases.

BACKGROUND: A limited number of studies have addressed the methods, indications and particular problems that may occur when programming prolonged intracranial pressure (ICP) monitoring in pediatric patients. Parenchymal fiberoptic transducers have been shown to give reliable ICP readings; moreover, they present a relatively low rate of complications, are easily placed and, as they are solid state, they are not subject to obstruction. MATERIAL/METHODS: A recently developed fiberoptic ICP transducer (Codman intraparenchymal sensor) was used to continuously monitor intracranial pressure in seventy children with non-traumatic neurosurgical diseases. The admitting diagnoses were hydrocephalus or shunt-related problems in 33 cases, single-suture (5 cases) or complex (16 cases) craniosynostosis in 21 patients, and sylvian scissure arachnoid cyst (SAC) in 16 cases. A software (ICP monitoring release) designed in our department was used for ICP recording storage and analysis. RESULTS: Raised ICP values were found in six of the seventeen patients with a suspected active hydyrocephalus, 24% of children with non-syndromic craniosynostosis, 52.8% of syndromic craniosynostosis patients, 50% or the children with a Type 11 SAC and two of the three patients with Type II SAC. CONCLUSIONS: Overall, prolonged ICP monitoring proved to be extremely useful in guiding surgical indications. The fiberoptic device used in our unit was shown to be reliable and associated with a relatively low rate of complications. Finally, the software allowed easy review and analysis of the obtained data.

Acquired Chiari type I malformation managed by supratentorial cranial enlargement.

INTRODUCTION: Acquired Chiari type-I malformation in hydrocephalic patients who have undergone surgical treatment was initially thought to depend on a craniocephalic disproportion induced by the cerebrospinal (CSF) shunt. However, most of the reports in the literature deal with children with lumbo-peritoneal shunts and emphasize the pathogenic role of the cranio-spinal pressure differential across the foramen magnum brought about by this type of shunt. METHOD: In the present report, the authors describe two further cases of symptomatic acquired Chiari type-I malformation observed in two adolescents operated on for correction of pseudotumor cerebri in one (lumbo-peritoneal shunt) and of a suprasellar arachnoid cyst (cysto-ventriculo-peritoneal shunt) in the other. RESULTS: In both subjects, both the clinical manifestations and the cerebellar tonsillar herniation regressed after supratentorial cranial expansion, without the need for any manipulation of the shunt devices implanted earlier. DISCUSSION: These results, together with the observation of the concomitant upward and downward herniation of the cerebellum in both patients, indicate that secondary craniocephalic disproportion plays a relevant role in the genesis of acquired Chiari type-I malformation in children bearing extrathecal CSF shunts.

Prolonged ICP monitoring in Sylvian arachnoid cysts.

BACKGROUND: The decision making process for patients with Sylvian fissure arachnoid cysts still represents a challenge for the neurosurgeon. A high percentage of patients are indeed asymptomatic, despite neuroimaging signs of apparently increased intracranial pressure (ICP). The present study was conducted to evaluate the usefulness of prolonged ICP recording in the preoperative work-up. METHODS: Eleven children (10 M/1 F) harboring temporal arachnoid cysts were investigated (mean age: 5.9 years). According to Galassi classification they were subdivided in three groups. Group I was made up of three patients with Type I cysts; Group II comprised six children with Type II cysts; Group III consisted of two children with Type III cysts. An extensible silicone microprocessor (Codman), developed for continuous ICP recording, was implanted intraparenchymally, adjacent to the major extension of the cyst. The collected information was cable unloaded to a PC and stored. All the patients underwent a minimum of 48 hours to a maximum of 72 hours of ICP continuous check. In resting conditions, 10 mm Hg was arbitrarily chosen as the upper normal limit of ICP, and the patients were classified according to the percentile distribution of their ICP daily and nightly pressure values. RESULTS: ICP recordings were in the normal range in all the three children with Type I cysts (49-86%< 10 mm Hg during the entire recording), despite the fact that two of them were apparently symptomatic. Three of the six children with a Type II temporal cyst had elevated ICP values (69-99%> 10 mm Hg), even though they had an incidental (1 case) or prenatal (2 cases) diagnosis. The remaining three patients had normal ICP values for more than 70% of the recording time period. The two patients with type III temporal arachnoid cysts had almost constantly abnormal ICP values (95-99%> 10 mm Hg). Five patients were operated; in four of them the surgical indication was based on ICP recordings (two of the three children with a Type II cyst and increased ICP and the two patients with a Type III cyst). The last child, harboring a Type I cyst, was operated upon parents' request, as a preventive measure. At a mean follow-up of 9.3 months all the patients operated on are in excellent clinical condition; one of them (Type II cyst) initially undergoing a craniotomy and cystic membrane excision required a subduro-peritoneal shunt implant 3 months after surgery for a symptomatic subdural hygroma on the side of the cyst. Postoperative computed tomography showed signs of brain expansion in the two patients operated on for a Type III cyst, and in the patient operated on for a Type I cyst. CONCLUSIONS: With the limit of the relatively small series presented here, prolonged ICP recording appeared to be an important preoperative tool to rule out the necessity of operating on children with Type I cysts. Furthermore, the study confirmed that an increase of the ICP is almost constantly present in children with Type III cysts. In cases of Type II lesions, the study results were less discriminating, though the ICP monitoring contributed in identifying those patients in whom surgery was indicated despite the absence of symptoms.