Human adipose tissue-derived mesenchymal stem cells (AT-MSCs) from various sites are applied in tissue engineering and cell therapy. The condition of AT-MSCs depends on the donor's age, body mass index (BMI), and gender. AT-MSCs from 66 human donors were analyzed, and the cells were sorted according to donor age (10-19 years: n = 1; 20-29 years: n = 5; 30-39 years: n = 12; 40-49 years: n = 22; 50-59 years: n = 12; 60-69 years: n = 9, and 70 years or older: n = 5), BMI (under 25, 25-30, and over 30), and gender (19 males and 48 females). Additionally, AT-MSCs were compared to bone marrow MSCs and chorionic tissue-derived MSCs. We measured the MSC yield, growth rate, colony-forming units, multipotency, and surface antigens. AT-MSC proliferation was greater in cells isolated from individuals aged less than 30 years compared to the proliferation of AT-MSCs from those over 50 years old. BMI was correlated with osteogenic differentiation potency; increased BMI enhanced osteogenesis. Adipogenic differentiation was more strongly induced in cells isolated from donors aged less than 30 years compared to those isolated from other age groups. Also, a BMI above 30 was associated with enhanced adipogenic differentiation compared to cells isolated from individuals with a BMI below 25. Bone marrow MSCs were strongly induced to differentiate along both osteogenic and adipogenic lineages, whereas AT-MSCs predominantly differentiated into the chondrogenic lineage. Therefore, the type of regeneration required and variations among potential donors must be carefully considered when selecting MSCs for use in applied tissue engineering or cell therapy.

Summary: Reconstruction of maxilla defects has remained one of the most challenging problems in craniomaxillofacial reconstruction because it typically requires harvesting and grafting of autologous bone, which poses limitations related to the difficulties in accurately reconstructing the defected bone and the highly prolonged duration of surgery. We employed tissue-engineered, patient-specific, 3-dimensional (3D)-printed biodegradable scaffolds for maxillofacial bone reconstruction in patients with complex maxillary defects after surgical removal of cancer. A customized polycaprolactone (PCL) scaffold was designed and fabricated for each patient. For this purpose, we used computer-aided design and manufacturing combined with 3D printing technology. The patients implanted with the PCL scaffolds were followed up for up to 2 years with careful evaluation of morphological changes in the face. We confirmed that the patient-specific 3D-printed PCL scaffold effectively filled the maxillary defect and promoted regeneration of the deficient tissue while remaining stable in the body for a relatively long period. Employing customized tissue-engineered scaffolds built using the patient’s computed tomography data and an extrusion-based 3D printing system is safe and clinically feasible, helping create and maintain improved morphological features of the face, which represents the most important aspect from the perspective of the patients.

Background: Silicon dioxide composites have been found to enhance the mechanical properties of scaffolds and to support growth of human adipose tissue-derived stem cells (hADSCs) both in vitro and in vivo. Silica (silicon dioxide alone) exists as differently sized particles when suspended in culture medium, but it is not clear whether particle size influences the beneficial effect of silicon dioxide on hADSCs. In this study, we examined the effect of different sized particles on growth and mitogen-activated protein kinase signaling in hADSCs. Methods: Silica gel was prepared by a chemical reaction using hydrochloric acid and sodium silicate, washed, sterilized, and suspended in serum-free culture medium for 48 hours, and then sequentially filtered through a 0.22 µm filter (filtrate containing nanoparticles smaller than 220 nm; silica NPs). hADSCs were incubated with silica NPs or 3 µm silica microparticles (MPs), examined by transmission electron microscopy, and assayed for cell proliferation, apoptosis, and mitogen-activated protein kinase signaling. Results: Eighty-nine percent of the silica NPs were around 50–120 nm in size. When hADSCs were treated with the study particles, silica NPs were observed in endocytosed vacuoles in the cytosol of hADSCs, but silica MPs showed no cell entry. Silica NPs increased the proliferation of hADSCs, but silica MPs had no significant effect in this regard. Instead, silica MPs induced slight apoptosis. Silica NPs increased phosphorylation of extracellular signal-related kinase (ERK)1/2, while silica MPs increased phosphorylation of p38. Silica NPs had no effect on phosphorylation of Janus kinase or p38. Pretreatment with PD98059, a MEK inhibitor, prevented the ERK1/2 phosphorylation and proliferation induced by silica NPs. Conclusion: Scaffolds containing silicon dioxide for tissue engineering may enhance cell growth through ERK1/2 activation only when NPs around 50–120 nm in size are included, and single component silica-derived NPs could be useful for bioscaffolds in stem cell therapy.