A Zn2+ cross-linked sodium alginate/epigallocatechin gallate hydrogel scaffold for promoting skull repair.

The optimal material for repairing skull defects should exhibit outstanding biocompatibility and mechanical properties. Specifically, hydrogel scaffolds that emulate the microenvironment of the native bone extracellular matrix play a vital role in promoting osteoblast adhesion, proliferation, and differentiation, thereby yielding superior outcomes in skull reconstruction. In this study, a composite network hydrogel comprising sodium alginate (SA), epigallocatechin gallate (EGCG), and zinc ions (Zn2+) was developed to establish an ideal osteogenic microenvironment for bone regeneration. Initially, physical entanglement and hydrogen bonding between SA and EGCG resulted in the formation of a primary network hydrogel known as SA-EGCG. Subsequently, the inclusion of Zn2+ facilitated the creation of a composite network hydrogels named SA-EGCG-Zn2+ via dynamic coordination bonds with SA and EGCG. The engineered SA-EGCG2 %-Zn2+ hydrogels offered an environment mimicking the native extracellular matrix (ECM). Moreover, the sustained release of Zn2+ from the hydrogel effectively enhanced cell adhesion, promoted proliferation, and stimulated osteoblast differentiation. In vitro experiments have shown that SA-EGCG2 %-Zn2+ hydrogels greatly enhance the attachment and growth of osteoblast precursor cells (MC3T3-E1), while also increasing the expression of genes related to osteogenesis in these cells. Additionally, in vivo studies have confirmed that SA-EGCG2 %-Zn2+ hydrogels promote new bone formation and accelerate the regeneration of bone in situ, indicating promising applications in the realm of bone tissue engineering.

Porous gelatin microsphere-based scaffolds containing MC3T3-E1 cells and calcitriol for the repair of skull defect.

There is an increasing demand for biomaterials with skull regeneration for clinical application. However, most of the current skull repair materials still have limitations, such as inadequate sources, poor cell adherence, differentiation, tissue infiltration, and foreign body sensation. Therefore, this study developed porous microsphere-based scaffolds containing mouse embryonic osteoblast precursor cells (MC3T3-E1 cells) and calcitriol (Cal) using gelatin and gelatin/hydroxyapatite through green freeze-crosslinking and freeze-drying. Gelatin was employed to prepare porous microspheres with a particle size of 100-300 µm, containing open pores of 2-70 µm and interconnected paths. Furthermore, the addition of Cal to porous gelatin microsphere-based scaffolds containing MC3T3-E1 cells (PGMSs-MC) and porous gelatin/hydroxyapatite composite microspheres containing MC3T3-E1 cells (HPGMSs-MC) improved their osteoinductivity and cell proliferation and promoted the formation of mature and well-organized bone. The developed Cal-HPGMSs-MC and Cal-PGMSs-MC displayed a good porous structure and cytocompatibility, histocompatibility, osteoconductivity, and osteoinduction. Thus, the designed scaffolds provide a promising prospect for tissue-engineered constructs with skull growth and integration, laying a foundation for further research on the reconstruction of skull defects.

[Application of two-stage operation on free latissimus dorsi myocutaneous flap transplantation and skull contour reconstruction in treatment of head titanium mesh exposure with soft tissue infection].

Objective: To explore the effectiveness of two-stage operation on free latissimus dorsi myocutaneous flap transplantation and skull contour reconstruction in the treatment of head titanium mesh exposure complicated with soft tissue infection. Methods: Between January 2015 and December 2021, 13 patients with head titanium mesh exposure complicated with soft tissue infection were admitted. There were 9 males and 4 females with a mean age of 42.9 years (range, 23-64 years). The duration of titanium mesh exposure was 22-609 days (median, 102 days). The wound site located at the frontal part in 3 cases, the parietal part in 1 case, the occipital part in 2 cases, the frontal-parietal part in 1 case, the temporal-parietal part in 4 cases, and the frontotemporal part in 2 cases. The titanium mesh had been taken out in 5 patients before admission, leaving skull defect and shape collapse, with signs of infection. The bacterial culture was positive in 7 cases and negative in 6 cases. The imaging examination revealed that the size of the skull defect ranged from 6 cm×5 cm to 21 cm×17 cm and the scalp defect ranged from 1 cm×1 cm to 15 cm×10 cm. The soft tissue infection did not reach dura in 5 cases, reached dura in 6 cases, and reached frontal sinus in 2 cases. The two-stage surgical protocol was used in all patients. In the first-stage operation, the latissimus dorsi myocutaneous flap was designed to repair the skull and scalp defects after removing the titanium mesh and thorough debridement. The size of muscle flap ranged from 13.5 cm×4.0 cm to 21.0 cm×17.0 cm, and the skin flap ranged from 7.0 cm×4.0 cm to 15.0 cm×10.0 cm. After the flap survived and stabilized, the second-stage operation was performed. The titanium mesh was implanted to reconstruct the skull contour. The size of titanium mesh ranged from 7.0 cm×6.0 cm to 21.5 cm×17.5 cm. The interval between the first- and second-stage operations was 3.7-17.8 months, with an average of 11.4 months. The survival of the skin flap, the appearance of the head, and the presence of re-exposed titanium mesh and infection were observed after operation. Results: At the first-stage operation, venous embolism occurred in 1 case, and no obvious abnormality was observed after treatment. All the flaps survived and the incisions healed by first intention. Besides, the incisions of the second-stage operation healed by first intention. All patients were followed up 1-96 months (median, 14 months). During follow-up, no exposure to titanium mesh, infection, or other complications occurred. The appearance satisfaction rate of the patients was 92.31% (11/13). There was no significant difference in the skull contour between the affected side and the healthy side in all patients. Conclusion: For the head titanium mesh exposure with soft tissue infection, the application of two-stage operation on free latissimus dorsi myocutaneous flap transplantation and skull contour reconstruction can reduce the risks of implant exposure and infection again by increasing the thickness of the scalp and blood supply, filling the wound cavity, and obtain good effectiveness.

Craneoplastías post-TEC en un único centro del Noroeste Argentino. Comparación de dos materiales / Post-ECT cranioplasties in a single center in the Argentine Northwest. Comparison of two materials

Introducción: Diversos estudios demuestran que la tasa de complicaciones asociadas a craneoplastías ha sido subestimada. A mediados de 2016 advertimos una serie de complicaciones asociadas a este procedimiento en nuestro Hospital. Por esto, se decidió cambiar el material que se utilizaba hasta entonces (i.e. polimetilmetracrilato de metilo, PMMAM) por otro distinto (i.e. Titanio). El objetivo del presente trabajo es analizar los resultados post-operatorios obtenidos con PMMAM versus Titanio. Materiales y Métodos: Estudio retrospectivo que incluye a 99 pacientes a los que se les realizó una craneoplastia en nuestro Hospital desde octubre de 2015 a octubre de 2018. Criterios de inclusión: defecto óseo causado tras una craniectomía post-TEC cerrado, sin signos infecciosos, operados en la misma sala operatoria, por el mismo quirúrgico y utilizando la misma técnica para cada material. Para el análisis estadístico se dividió a la muestra en 2 grupos: PMMAM (n= 44) versus Titanio (n=55). Resultados: El 85% (n=86) eran de sexo masculino y la edad promedio fue 29 años (rango: 17-63 años). Se observó una diferencia estadísticamente significativa respecto a los pacientes que desarrollaron determinadas complicaciones entre el grupo PMMAM y el grupo Titanio: colección líquida inflamatoria epidural (14% vs 0%; p=0,006); infección del sitio quirurgico (9% vs 0%; p=0,036) y remoción quirúrgica de la plaqueta (16% vs 0%; p=0,003). Conclusión: Con el uso de malla de titanio se disminuyeron significativamente las complicaciones post-operatorias, respecto al uso de PMMAM

Introduction: Various studies show that the rate of complications associated with cranioplasties has been underestimated. In mid 2016 we noticed a series of complications associated with this procedure in our Hospital. For this reason, it was decided to change the material used until then (i.e. methyl polymethylmethacrylate, PMMAM) for a different one (i.e. Titanium). The objective of this work is to analyze the post-operative results obtained with PMMAM versus Titanium. Materials and Methods: Retrospective study including 99 patients undergoing cranioplasty in our Hospital from October 2015 to October 2018. Inclusion criteria: bone defect was caused after a closed post-TEC craniectomy, without infectious signs, operated in the same operating room, by the same surgeon and using the same technique for each material. For statistical analysis, the sample was divided into two groups: PMMAM (n= 44) versus Titanium (n=55). Results: 85% (n=86) were male and the average age was 29 years (range: 17-63 years). A statistically significant difference was observed with respect to patients who developed certain complications between the PMMAM group and the Titanium group: epidural inflammatory liquid collection (14% vs 0%; p=0.006); surgical site infection (9% vs 0%; p=0.036) and surgical removal of the platelet (16% vs 0%; p=0.003). Conclusion: The use of titanium mesh significantly reduced post-operative complications with respect to the use of PMMAM

Clinical analysis of cranioplasty combined with shunt in the treatment of skull defect complicated with hydrocephalus after craniocerebral trauma / 中国神经精神疾病杂志

Objective To evaluate the clinical efficacy of ventricle -peritoneal or ventricle-atrial shunt in the treatment of skull defect with craniocerebral trauma combined with hydrocephalus in the same period. Methods Sixty-four patients with skull defect after craniocerebral trauma combined with hydrocephalus were randomly divided into observation group (n=32) and control group (n=32) The ventricle-peritoneal or ventricle-atrial shunt and skull repair were conducted simultaneously following surgical operation in observation group whereas ventricle-peritoneal or ventricle-atrial shunt and the skull defect were performed within 3 months and after 3 months following operation, respectively. The hydrocephalus symptoms, prognosis after three months ,clinical outcomes and the postoperative complications were evaluated. Results There was no significant difference in hydrocephalus symptoms between the observation group and control group (χ2=0.005,P>0.05). The GCS score, GOS score and neurological function score after three months were better than those before the treatment in these two groups (P<0.05). These functional parameters were significantly better in the observation group than in control group (P<0.05). The good rate in three months was significantly higher in the observation group than in control group (59.38％vs 31.25％,χ2=7.23, P<0.05). The incidence of complication was 6.25％(2/32) in the observation group, which was significantly lower than that in the control group (31.25％, 10/32) (χ2=7.13, P<0.05).Conclusion Cranioplasty combined with shunt in the treatment of skull defect complicated with craniocerebral trauma-associated hydrocephalus has low postoperative complications, good clinical prognosis and reliable efficacy, which is worthy of clinical application.

Clinical curative effect and complications of digital three-dimensional molding of titanium mesh for repairing skull defect / 中国医师进修杂志

Objective To explore the clinical curative effect and complications of digital three-dimensional molding of titanium mesh for repairing skull defect. Methods The clinical data of 42 patients having underwent repairing skull defect with three-dimensional molding of titanium mesh were retrospectively analyzed. Results The average operation time was about 2 h, and 42 patients were operated successfully. The bilateral skull was symmetry and the appearance was good. In 42 patients, subcutaneous dropsy occurred in 1 case, epilepsy occurred in 3 cases, and intracranial bleeding again surgery occurred in 1 case. Patients were satisfied with the results of cranioplasty. Conclusions Repairing skull with digital three-dimensional molding of titanium mesh is simple, with shorter operation time, lower operation risk, and lower postoperative complication, and the clinical curative effect is satisfactory.