Hydrophilic surface-modified 3D printed flexible scaffolds with high ceramic particle concentrations for immunopolarization-regulation and bone regeneration.

Bioceramic scaffolds used in bone tissue engineering suffer from a low concentration of ceramic particles (<50 wt%), because the high concentration of ceramic particles increases the brittleness of the composite. 3D printed flexible PCL/HA scaffolds with high ceramic particle concentrations (84 wt%) were successfully fabricated in this study. However, the hydrophobicity of PCL weakens the composite scaffold hydrophilicity, which may limit the osteogenic ability to some extent. Thus, as a less time-consuming, less labour intensive, and more cost-effective treatment method, alkali treatment (AT) was employed to modify the surface hydrophilicity of the PCL/HA scaffold, and its regulation of immune responses and bone regeneration were investigated in vivo and in vitro. Initially, several concentrations of NaOH (0.5, 1, 1.5, 2, 2.5, and 5 mol L-1) were employed in tests to determine the appropriate concentration for AT. Based on the comprehensive consideration of the results of mechanical experiments and hydrophilicity, 2 mol L-1 and 2.5 mol L-1 of NaOH were selected for further investigation in this study. The PCL/HA-AT-2 scaffold dramatically reduced foreign body reactions as compared to the PCL/HA and PCL/HA-AT-2.5 scaffolds, promoted macrophage polarization towards the M2 phenotype and enhanced new bone formation. The Wnt/ß-catenin pathway might participate in the signal transduction underlying hydrophilic surface-modified 3D printed scaffold-regulated osteogenesis, according to the results of immunohistochemical staining. In conclusion, hydrophilic surface-modified 3D printed flexible scaffolds with high ceramic particle concentrations can regulate the immune reactions and macrophage polarization to promote bone regeneration, and the PCL/HA-AT-2 scaffold is a potential candidate for bone tissue repair.

Photo-crosslinked bioactive BG/BMSCs@GelMA hydrogels for bone-defect repairs.

The clinical treatments of bone defects remain a challenge. Hydrogels containing bone marrow mesenchymal stem cells (BMSCs) are extensively used to bone regeneration because of excellent biocompatibility and hydrophilicity. However, the insufficient osteo-induction capacity of the BMSC-loaded hydrogels limits their clinical applications. In this study, bio-active glass (BG) and BMSCs were combined with gelatin methacryloyl (GelMA) to fabricate composite hydrogels via photo-crosslinking, and the regulation of bone regeneration was investigated. In vitro experiments showed that the BG/BMSCs@GelMA hydrogel had excellent cytocompatibility and promoted osteogenic differentiation in BMSCs. Furthermore, the BG/BMSCs@GelMA hydrogel was injected into critical-sized calvarial defects, and the results further confirmed its excellent angiogenetic and bone regeneration capacity. In addition, BG/BMSCs@GelMA promoted the polarization of macrophages towards the M2 phenotype. In summary, this novel composite hydrogel demonstrated remarkable potential for application in bone regeneration due to its immunomodulatory, excellent angiogenetic as well as osteo-induction capacity.

[Comparative analysis of clinical features of primary and secondary laryngeal tuberculosis].

Objective:The aim of this study was to analyze and compare the clinical pattern, diagnosis and treatment in primary and secondary laryngeal and pharyngeal TB. Methods:A retrospective analysis was carried out on 103 patients diagnosed laryngeal tuberculosis in our department. Characteristics of demography, life-style, clinical features, diagnosis and treatment were obtained from medical case records. Clinical analysis of 103 patients with pathologically confirmed laryngeal TB was carried out retrospectively in the second affiliated hospital of Nanchang university in Jiangxi province. Results:Among 103 patients, 64 cases were diagnosed as primary laryngeal TB and 39 cases were diagnosed as secondary laryngeal TB. The most common complaints were hoarseness and odynophagia. The true and the false vocal cords were most commonly involved. Most patients with primary tuberculosis of the larynx present a single, hyperplastic lesion.Secondary laryngeal TB of larynx was characterized by ulcers, edema effusive, multiple sites lesions. The anti-TB treatment was given systemically to all patients. The surgery should be considered if the patient has a laryngeal obstruction. Conclusion:The clinical manifestations and signs of primary and secondary tuberculosis of the larynx are different. Laryngeal tuberculosis is easy to be misdiagnosed as laryngitis and laryngeal tumors. Pathological examination should be performed to confirm the diagnosis.

Unique WSPA protein from terrestrial macroscopic cyanobacteria can confer resistance to osmotic stress in transgenic plants.

The terrestrial macroscopic cyanobacterium Nostoc commune exhibits remarkable resistance to desiccation stress. This species synthesizes abundant acidic water stress protein (WSPA) in cells upon desiccation and secretes it into the extracellular polysaccharide sheath upon rehydration. However, our knowledge about its cellular role in stress resistance is still rather limited. In this paper, we first revealed that WSPA also occurred in two other macroscopic cyanobacteria Nostoc flagelliforme and Nostoc sphaeroides, but it is more abundant in N. commune. The N. commune wspa1 gene was then heterologously expressed in Arabidopsis thaliana. Phenotypic observation found that WSPA1 conferred increased tolerance to osmotic stress in transgenic plants. The physiological indexes such as relative electrolyte leakage, malondialdehyde, proline accumulation and the maximal quantum efficiency of Photosystem II, were also improved in transgenic plants upon osmotic stress, compared to wild types. In addition, GFP fluorescence analysis of eGFP::wspa1 transgenic plant showed that WSPA1 was localized in the cytoplasm. Therefore, the role of WSPA revealed by this study mainly represented its intracellular function. In general, our research suggested that WSPA may act as a stress protein and involve cellular osmotic stress resistance.

Quality evaluation of the edible blue-green alga Nostoc flagelliforme using a chlorophyll fluorescence parameter and several biochemical markers.

Nostoc flagelliforme is an edible blue-green alga with herbal and dietary values. Due to the diminishing supply of natural N. flagelliforme and the large investment on the development of its cultivation technology, it is anticipated that artificially cultured N. flagelliforme will soon sustain the market supply. Once this change occurs, the storage-associated quality problem will become the focus of attention for future trade. In this paper, we used a chlorophyll fluorescence parameter, maximum quantum efficiency of Photosystem II (Fv/Fm), and several biomarkers to evaluate the quality of several N. flagelliforme samples. It was found that longer storage times resulted in darker coloured solutions (released pigments) and decreased amounts of chlorophyll a (Chl a) and water-soluble sugars (WSS). Additionally, a higher Fv/Fm value suggests better physiological recovery and quality. In actual application, determination of Fv/Fm would be the first step for evaluating the quality of N. flagelliforme, and the biochemical indexes would serve as good secondary markers.

Resurfacing partial nose defects with a retroauricular skin/cartilage free flap.

BACKGROUND: The retroauricular skin has always received much attention by plastic surgeons for use in nose reconstruction because of its rich vascularity. Anatomically, the skin of this area lies hidden behind the ear and is very similar to that of the face. More importantly, the retroauricular skin flap along with the cartilage can be used to repair defective cartilage of the nose. All these reasons make this area an ideal donor site for nose reconstruction. This article presents the surgical procedures for reconstruction of partial nasal defects with the use of retroauricular skin/cartilage free flaps. METHODS: Based on the anatomy and blood supply of the retroauricular region, a flap was designed and harvested with the retroauricular vessels as its pedicle. This flap was used to repair the partial nose defects in 10 patients, between the years 2002 and 2008. Of these, 4 patients presented with unilateral ala defects; 2 with nasal tip defects; 2 with defects on the nasal tip and bilateral ala; 1 with unilateral ala and tip defect; and 1 with unilateral ala and lateral defect. The size of the defect ranged from 2.5 × 1.5 cm to 4.0 × 3.0 cm. The flap varied between 3.0 × 2.0 cm and 4.5 × 3.5 cm. In all cases, the auricular cartilage of 1.5 × 1.0 cm to 1.0 × 0.5 cm was taken along with the flap. The retroauricular vessels were anastomosed with the facial vessels. The donor site was covered with full-thickness skin graft or local flap. RESULTS: No flap failure was recorded. Excellent morphologic reconstruction was obtained with these flaps with no sequela at the donor site in terms of form and function. Postoperatively, the blood supply to the flaps was fairly good in 8 cases, although there was vein congestion in 2 cases on the fourth day. However, the postoperative results of the 10 cases were satisfactory after treatment. CONCLUSION: The retroauricular skin-cartilage free flap is a good choice for partial nasal reconstruction, having the merits of a well-hidden donor site, good color match, and 1-stage operation for cartilage support and nose reconstruction.

A simple, minimally invasive method for creation of the superior palpebral fold in Asians with the modified continuous buried tarsal stitch: a joint assessment from Toronto, Ontario, Canada, and Chengdu, China.

A simple, minimally invasive stitch method to construct the superior palpebral fold in Asian upper eyelids is described. With the use of a clear 6-0 monofilament polypropylene suture and a continuous stitch and by securing multiple consecutive transcutaneous intratarsal fixations, we were able to produce a consistent, natural result with high success rates and no noticeable scarring in 1648 cases over a 9-year period at 2 surgical centers in Toronto, Ontario, Canada, and Chengdu, China.

Wedge-shaped excision and modified vertical mattress suture fully buried in a multilayered and tensioned wound closure.

BACKGROUND: A successful deep multilayered wound suture should provide a firm tension-relieving closure, good wound-edge eversion, hemostasis, and minimal intradermal extraneous materials. However, this is not always achieved with a single standard technique. The authors describe their modification of a wound closure method that can rapidly and reliably achieve these results. METHODS: A wedge-shaped excision was adopted to obtain a trapezoid pattern transect, after which a modified fully buried vertical mattress suture technique was used to close the wound. These techniques were compared with the standard excision and suture techniques used for the same patient at different times after surgery. RESULTS: The wedge-shaped excision can facilitate good wound-edge eversion, and the modified fully buried vertical mattress suture can provide firm tension relief and optimal apposition. Compared with conventional excision and suture techniques, the described techniques brought about a better outcome in terms of hypertrophic scar prevention. CONCLUSION: The described modified technique seems to be more efficient than conventional procedures used to prevent hypertrophic scar formation.

Repair of faciocervical scars by expanded deltopectoral flap.

OBJECTIVE: To explore the approach to repair faciocervical scars. METHODS: Eighty-six patients with large faciocervical scars were repaired using the expanded deltopectoral flaps. After expansion, the flaps were transpositioned to repair faciocervical scars. Three weeks later the pedicles were separated and their skin tubes were flattened for the repair of the remaining faciocervical scars. RESULTS: Of the 86 cases, 80 achieved effective results with all the flaps surviving. Six cases showed achromatosis after healing because of the compromised blood supply. CONCLUSION: The application of expanded deltopectoral flaps is proved to be an effective way of repairing faciocervical scars. The flaps are as thin as those subdermal vascular network flaps', so when transferred to the facial region, the flaps will not swell and can well match with their peripheral tissues.

[The design of the expanded flap for the repair of the temporal and cheek area].

OBJECTIVE: To explore the design of an expanded flap at the temporal and cheek area. METHODS: The expanded flap was used for the repair of 619 temporal and cheek defects secondary to scar, nevus or hemangioma excision. In the frontal area, the rotational flap was usually used. For the repair of the cheek, the applied flap included the rotational, advanced, and transposition flap from the neck, as well as the pedicle flap from the thoracic area. RESULTS: Eight thoracic-deltoid flaps had distal necrosis of 1 approximately 5 cm. Of them, 5 flaps were repositioned with subsequent good result; the other 3 flaps underwent skin grafting. The five facial expanded flaps showed distal necrosis of 0.5 approximately 1 cm. Of them, 4 flaps occurred delayed healing, 1 flap underwent skin grafting. Expander extrusion happened in 41 cases (6.62%), which resulted in deficiency of the expanded area. Satisfactory results were achieved in all the other cases. CONCLUSIONS: According to our experience, careful design of the flap is very important for obtainingbetter surgical results and decreasing complications.

Local hatchet flap for facial skin defects reconstruction in special areas.

BACKGROUND: The local hatchet flap has been used to reconstruct skin defects of the face with satisfactory results. Cosmetically, it has advantages over other local flaps when skin defects are located in special areas such as the eyelid. OBJECTIVE: The purpose of this study was to examine the application of local hatchet flaps for facial defect reconstruction, especially in cases where reconstruction is classically difficult for cosmetic and functional rehabilitation. METHODS: We report an illustrated case series. Results. In this study, all four cases achieved satisfactory functional and cosmetic results using the local hatchet flap. CONCLUSIONS: The local hatchet flap is an effective and simple alternative for reconstructing facial defects in special areas of the face, offering good cosmetic results and satisfactory function.

[Management of severe postburn scar contracture in the lower extremities].

OBJECTIVE: To summarize the clinical experience in the management of severe postburn scar contracture in the lower extremities. METHODS: The scars in popliteal fossa and ankle joint were excised. Traction and skin grafting were employed in the management of contracture deformity in these areas. RESULTS: Severe postburn scar contracture deformity in sixty postburn patients could be corrected by constant traction and skin grafting. CONCLUSION: Scar excision and lysis with constant traction might be an optimal method in the management of severe postburn scar contracture deformity of joints in the lower extremities and satisfactory results could be obtained without tendon grafting and elongation.

[Experimental study of tissue engineered blood vessel with vascular endothelial cell and vascular smooth muscle cell].

OBJECTIVE: To investigate the feasibility to seed vascular endothelial cell(VEC) and vascular smooth muscle cell (VSMC) into tissue engineered blood vessel scaffold material. METHODS: 1. A blood vessel scaffold with a combined polymer was designed, which mainly is composed of rabbit VSMC and collagen with reinforcement by a non-spinning fabric mesh made of polyglycolic acid (PGA). 2. VEC were isolated from rabbit thoracic aorta by enzyme digestion methods and subcultured and purified. Then the cells were seeded into scaffold material. The morphological characteristics of tissue engineered blood vessel was analyzed by scanning electron microscopy. RESULTS: VEC could adhere well to the inner surface of the tissue engineered tubular scaffold material with a tenacity and elasticity. VSMC could sustain bioactivity of cell. CONCLUSION: Non-spinning PGA porous biodegradable materials coated with collagen is benefit for cells to adhere and grow. It will lay a foundation of a laminated structure of tissue engineered blood vessel.

[Fabrication of a blood vessel scaffold with a combined polymer for tissue engineering].

OBJECTIVE: To investigate the possibility to fabricate a blood vessel scaffold with a combined polymer for tissue engineering. METHODS: A blood vessel scaffold was designed with a combined polymer composed of rabbit vascular smooth muscle cells(VSMCs), collagen and a non-spinning fabric mesh of polyglycolic acid (PGA). VSMCs were implanted into collagen gel and their growth was observed. The mixed solution of VSMCs and collagen was dropped into the tubular scaffold, followed by 7-day culturing. RESULTS: VSMCs formed many prominences after culturing in gelatinous collagen for 3-4 hours. With cells extending, some cells became shuttle- or spindle-shaped. After VSMCs-collagen complex was implanted into the PGA mesh, most of VSMCs remained in the pore of PGA mesh with the formation of gelation. VSMCs could adhere to and grow on the PGA fiber. CONCLUSION: The non-spinning PGA porous biodegradable material coated with collagen is a good carrier for VSMCs to adhere and grow.

[Computer-aided tissue expansion 3D profilometry and surgery planning system].

OBJECTIVE: To develop and evaluate the computer-aided system in measurement of expanded skin and preoperative planning. METHODS: Stereophotogrammetric technique was used to gain the 3D image-pairs, from which the contours of the expanded sites were restored. The 3D surface data were provided to the specially developed "computer-aided tissue expansion 3D profilometry and surgery planning system", to calculate the expansion area and help the preoperative design. RESULTS: The system has been applied clinically in 16 tissue expansion sites of 11 patients with fairly good results since March 1999. Compared with the traditional method, this system is accurate, repeatable and feasible. CONCLUSION: This technique is useful and promising for improving the operation of tissue expansion.

[Reconstruction of partial nose defects with retroauricular free flap transplantation].

OBJECTIVE: To present the operation for nose defect reconstruction using a retroauricular free flap and the auricle cartilage. METHODS: Based on the anatomy and blood supply of the retroauricular region, a flap was designed and harvested with the posterior auricular vessels as its pedicle. The flap was used to repair nose defects in five patients. Of them, three had unilateral subtotal alinasal defects, one had nasal apex defect, and one had defects on nasal apex and bilateral ala. The size of the defect ranged from 2.5 cm x 1.5 cm to 3.0 cm x 4.0 cm. The flap varied between 3.0 cm x 2.0 cm and 4.5 cm x 3.5 cm. In 4 cases, the auricular cartilage of 2.0 cm x 1.5 cm to 1.5 cm x 1.0 cm was taken along with the flap. The posterior auricular vessels were anastomosed with the facial vessels. The donor site was covered with full-thickness skin graft. RESULTS: Postoperatively, the blood supply to the flaps was fairly good in 3 cases, while there was various venous stasis in 2 cases during the first 4 days. However, the postoperative results of the 5 cases were satisfactory. CONCLUSIONS: The retroauricular free flap is a good choice for partial nose reconstruction, which had the merits of well-hidden donor site, good color match, and one-stage operation.

[Rhinoplasty of unilateral cleft lip].

OBJECTIVE: To investigate the technique for unilateral cleft lip nasal deformities. METHODS: Through the traditional columella margin incision, the alar cartilage and the lateral nasal cartilage were exposed. After the mucosa between the two cartilages was divided, a mucosa-cartilage flap was developed and anchored, moving the lateral crus upwardly and medially, correcting the nasal deformity. RESULTS: 52 cases of primary nasal deformities and 18 cases of secondary nasal deformities were corrected with this technique. Satisfactory results were achieved. CONCLUSION: This technique is recommendable, which is more likely to restore the physiological characters of the nose than the conventional technique.

[The expanded distant skin flap and its application].

OBJECTIVE: To summarize and present the experiences and results of the expanded distant skin flaps used in plastic and reconstructive operations. METHODS: 102 patients who had undergone expanded distant skin flap transfer were reviewed and followed up. RESULTS: Good results were obtained. Especially when there was no sufficient normal skin close to the lesion or defect, the distant skin flaps were employed. The expanded distant skin flap can be directly transferred as a pedicle skin flap or an island skin flap. It can be indirectly transferred with an intermediary carrier or as a free skin flap. CONCLUSION: The expanded distant skin flaps have many advantages, indications, worthy of recommendation.

[Preparation of compound biodegradable matrices and growth of vascular endothelial cell on them].

OBJECTIVE: To prepare the compound biodegradable matrices, polyglycolic acid (PGA), polylactic acid (PLA) mesh and poly-beta-hydroxybutyrate(PHB) which precoated with collagen, and to observe the growth and differentiation of bovine vascular endothelial cells on these scaffolds. METHODS: By enzymatic digestion methods, bovine vascular endothelial cell (VEC) were isolated from calf thoracic aorta, then cultured and purified. PGA, PLA, PHB meshes were dipped into cross-linked type I collagen solution, dried under vacuum frozen condition. VEC were seeded into these scaffolds. The growth of VEC on scaffolds was analyzed by MTT method. RESULTS: The collagen, PGA/collagen, PLA/collagen scaffolds were elasticity and tenacity. VEC grew better on collagen, PGA/collagen, and PLA/collagen membranes than on the PHB/collagen one. CONCLUSION: The PGA/collagen scaffold has elasticity, plasticity and tenacity. VEC grow best on it. It is an ideal scaffold for tissue engineered vessel reconstruction for it integrating both advantages of biomaterials and degradable materials.