The Impact of Centrifugal Force on Isolation of Bone Marrow Mononuclear Cells Using Density Gradient Centrifugation.

BACKGROUND: Bone marrow mononuclear cells (BMMNCs) have great potential in bone regenerative therapy. The main method used today to obtain BMMNCs is Ficoll density gradient centrifugation. However, the centrifugal force for this isolation method is still suboptimal. OBJECTIVES: To determine the optimal centrifugal force in Ficoll density gradient centrifugation of bone marrow (BM) to achieve high stem/progenitor cell content BMMNCs for regenerative therapy. METHODS: BM was aspirated from nine minipigs and divided into three groups according to different centrifugal forces (200 g, 300 g and 400 g). Immediately after BMMNCs were obtained from each group by Ficoll density gradient centrifugation, residual red blood cell (RBC) level, nucleated cell counting, viability and flow cytometric analyses of apoptosis and reactive oxygen species (ROS) generation were measured. The phenotypic CD90 and colony formation analyses of BMMNCs of each group were performed as well. Bone marrow-derived mesenchymal stem cells (BMSCs) were harvested at passage 2, then morphology, cell phenotype, proliferation, adipogenic, chondrogenic and osteogenic lineage differentiation potential of BMSCs from each group were compared. RESULTS: The 300 g centrifugal force was able to isolate BMMNCs from BM with the same efficiency as 400 g and provided significantly higher yields of CD90+ BMSCs and fibroblastic colony-forming units of BMSC (CFU-f(BMSC)), which is more crucial for the regenerative efficacy of BMMNCs. Meanwhile, 200 g hosted the most RBC contamination and minimum CFU-f (BMSC) yield, which will be disadvantageous for BMMNC-based cell therapy. As for in vitro cultured BMSCs which were isolated from BMMNCs by different centrifugal forces, no significant differences were found on morphology, cell proliferation rate, phenotypic marker, adipogenic, chondrogenic and osteogenic differentiation potential. CONCLUSIONS: 300 g may be the optimal centrifugal force when using Ficoll density gradient centrifugation to isolate BMMNCs for bone regenerative therapy. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Volumetric Analysis of Unilateral Alveolar Bone Defect Using Modified Subtraction in Older Chinese Patients.

A large number of older patients (≥13 y old) with alveolar clefts missed the optimal alveolar bone grafting time period in China. This study aimed to determine the accuracy and repeatability of modified computer-aided engineering subtraction for volumetric measurement of these patients. In addition, the study aimed to determine whether the volume of defect is correlated with cleft type (cleft lip and alveolus, cleft lip and palate), cleft location, age, and sex. Preoperative computed tomography data from 100 patients of unilateral alveolar cleft patients without secondary alveolar bone grafting were measured using 2 methods. The maxillary resin model around the alveolar cleft was printed using the 3-dimensional (D) printing method, and the volume of the defect was measured using the drainage method. In the modified subtraction method, Mimics software was used to simulate fracture filling by layer drawing, and the defect volume was determined by subtracting the preoperative fracture template from the filled 3D skull template. The mean time taken to calculate an alveolar cleft defect volume by modified subtraction method was 3.2 minutes. The average defect volume measured using the 3D printing and modified subtraction methods were 1.58±0.41 and 1.55±0.42 cm 3 , respectively. Findings suggest that cleft location and age do not affect the defect volume of older patients with alveolar cleft, unlike cleft type and sex. The modified computer-aided subtraction method provides good accuracy, consistency, and reproducibility in measuring alveolar ridge defect volume. Moreover, this method is more efficient and cost-effective than the 3D-printed model method.

Anatomic and Magnetic Resonance Imaging-Based Correction of Upper-Eyelid Depression and Blepharoptosis in Senile Patients.

In senile patients with sunken superior sulcus, involutional ptosis, and higher eyelid crease, a single operation to correct depression or ptosis cannot achieve good results. We demonstrated the anatomy of periorbital septum fibers, which may contribute to the levator muscle's volume depletion and dynamic power transmission disorder, and described a procedure for correcting upper-eyelid depression and blepharoptosis in senile patients. The fibrous webs in these patients connected the posterior aspect of the orbicularis and the orbital septum and extended to the orbital fat and levator aponeurosis. These fibers were dissected to release the periorbital septal fibers, and the orbital septal fat flap was transferred to the depressed region. Advancement or plication of the levator aponeurosis was performed in patients with uncorrected blepharoptosis after the procedures described above. The technique was applied to 13 Chinese patients (25 eyes) between May 2021 and April 2022. Postoperative magnetic resonance imaging revealed that the preaponeurotic fat was displaced forward and down to the upper margin of the tarsus, and the curvature of the upper-eyelid depression was significantly improved. Moreover, the superior sulcus deformity improved, the ptosis was corrected, and the uppermost crease decreased in all patients. No recurrence of ptosis or abnormal adhesion was observed. We believe this is the first study using magnetic resonance imaging to evaluate eyelid anatomy and the effects of surgery in this patient group. Releasing periorbital septum fibers is crucial for correcting a portion of the sunken eyelid and ptosis in Asians.

A Modified Technique in Rhinoplasty: A Septal Extension Graft Complex Using Septal Cartilage, Ethmoid Bone, and Auricular Cartilage.

BACKGROUND: Due to the small and weak septal cartilage of Asians, it is a challenge to obtain ideal tip projection and nose lengthening in this population by performing septal extension grafts with only septal cartilage. OBJECTIVES: The aim of this study was to introduce a septal extension graft complex incorporating nasal septal cartilage, the perpendicular plate of the ethmoid bone, and bilateral auricular cartilage, and to examine its effectiveness in terms of morphological and mechanical support. METHODS: Septal cartilage was harvested under an endoscope according to standard techniques. Two pieces of the perpendicular plate of the ethmoid bone, placed on either side of the "L" strut, served as 2 spreader grafts. A double layer of auricular cartilage was fixed as columellar strut grafts. Three-dimensional facial scanning was used to examine the change of 3 parameters. Nasal tip resistance was evaluated by a digital Newton meter. RESULTS: In total, 25 patients were followed up postoperatively for a mean of 25.9 months. The analysis showed significant differences in both contour parameters and nasal resistance: nasal length (mean [standard deviation], 41.4 [4.0] vs 46.2 [3.4] mm, P < 0.05) and nasal tip projection (21.3 [3.2] vs 24.4 [2.7] mm, P < 0.05) appeared to increase postoperatively, whereas nasolabial angle (117.6° [5.9°] vs 109.5° [5.3°], P < 0.05) showed a significant decrease after surgery. The resistance of the nasal tip also increased significantly (P < 0.05) at displacements of 1, 2, and 3 mm. All patients were satisfied with the aesthetic results, and no serious complications occurred. CONCLUSIONS: This kind of modified septal extension graft technique can effectively adjust nasal morphology for short-nose East Asians.