Femtosecond laser microprinting of a polymer fiber Bragg grating for high-sensitivity temperature measurements.

We demonstrate the microprinting of a novel suspended polymer fiber Bragg grating for high-sensitivity temperature measurements. The proposed sensor was developed using a femtosecond laser-induced multiphoton polymerization technique. The grating was cured in a single-groove silica tube spliced between two single-mode fibers. Its transmission spectrum, mode field, and temperature response were thoroughly investigated. A sensitivity of -220 pm/°C was achieved over a temperature range of 24°C to 40°C, which is meaningful in biosensing applications. This all-in-fiber polymer Bragg grating exhibits high temperature sensitivity, excellent mechanical strength, and ultrahigh integration. As such, a temperature sensing element of this type would be a beneficial tool for biological measurements.

Reconstruction of Corner of Mouth for Elder Facial Paralysis by Suspension Nasolabial Fold Dermal Tissue Flap: A Modified Method.

A modified method based on existing static facial sling techniques to reconstruct the corner of mouth for elder facial palsy was developed and reported. According to the anatomy and function of the zygomatic minor and zygomatic major, this technique uses nasolabial dermis as a whole to attach to the orbicularis oris to provide attachment to the whole area. Therefore, in our method, the function of the zygomaticus minor and zygomaticus major were reconstructed by attaching to the zygomatic arch periosteum through such slings. This procedure is effective in improving facial symmetry and obtaining inconspicuous scarring. We believe that our technique is a simple, effective and reliable option for elder facial paralysis.

Recent progress of collagen, chitosan, alginate and other hydrogels in skin repair and wound dressing applications.

Human understanding of skin is constantly ongoing. Great progress has been made in skin repair, wound dressing regeneration biomaterials research in recent years. This review introduced the clinical research and guiding principles of skin repair, wound dressing biomaterials at home and abroad, introduced the classification of various skin repair and wound dressing, listed the composition and performance of different dressing biomaterials, including traditional, natural, synthetic, tissue-engineered dressing materials were extensively reviewed. The biological molecular structures and biological function characteristics of different dressing biomaterials are comprehensively reviewed. Collagen, chitosan, alginate hydrogels et al. as the most popular biological macromolecules in skin repair and wound dressing applications were reviewed. The future development direction is also prospected. This paper reviews the research progress of advanced functional skin repair and wound dressing, which provides a reference for the modifications and applications of wound dressings.

Smart biomaterials and their potential applications in tissue engineering.

Smart biomaterials have been rapidly advancing ever since the concept of tissue engineering was proposed. Interacting with human cells, smart biomaterials can play a key role in novel tissue morphogenesis. Various aspects of biomaterials utilized in or being sought for the goal of encouraging bone regeneration, skin graft engineering, and nerve conduits are discussed in this review. Beginning with bone, this study summarizes all the available bioceramics and materials along with their properties used singly or in conjunction with each other to create scaffolds for bone tissue engineering. A quick overview of the skin-based nanocomposite biomaterials possessing antibacterial properties for wound healing is outlined along with skin regeneration therapies using infrared radiation, electrospinning, and piezoelectricity, which aid in wound healing. Furthermore, a brief overview of bioengineered artificial skin grafts made of various natural and synthetic polymers has been presented. Finally, by examining the interactions between natural and synthetic-based biomaterials and the biological environment, their strengths and drawbacks for constructing peripheral nerve conduits are highlighted. The description of the preclinical outcome of nerve regeneration in injury healed with various natural-based conduits receives special attention. The organic and synthetic worlds collide at the interface of nanomaterials and biological systems, producing a new scientific field including nanomaterial design for tissue engineering.

Preparation and application of chitosan biomaterials in dentistry.

Chitosan is a biodegradable and biocompatible natural polysaccharide that has a wide range of applications in the field of dentistry due to its functional versatility and ease of access. Recent studies find that chitosan and its derivatives can be embedded in materials for dental adhesives, barrier membranes, bone replacement, tissue regeneration, and antimicrobial agent to better manage oral diseases. In this paper, we provide a comprehensive overview on the preparation, applications, and major breakthroughs of chitosan biomaterials. Furthermore, incorporation of chitosan additives for the modification and improvement of dental materials has been discussed in depth to promote more advanced chitosan-related research in the future.

Chondrocyte-laden GelMA hydrogel combined with 3D printed PLA scaffolds for auricle regeneration.

The current gold standard for auricular reconstruction after microtia or ear trauma is the autologous cartilage graft with an autologous skin flap overlay. Harvesting autologous cartilage requires an additional surgery that may result in donor area complications. In addition, autologous cartilage is limited and the auricular reconstruction requires complex sculpting, which requires excellent clinical skill and is very time consuming. This work explores the use of 3D printing technology to fabricate bioactive artificial auricular cartilage using chondrocyte-laden gelatin methacrylate (GelMA) and polylactic acid (PLA) for auricle reconstruction. In this study, chondrocytes were loaded within GelMA hydrogel and combined with the 3D-printed PLA scaffolds to biomimetic the biological mechanical properties and personalized shape. The printing accuracy personalized scaffolds, biomechanics and chondrocyte viability and biofunction of artificial auricle have been studied. It was found that chondrocytes were fixed in the PLA auricle scaffolds via GelMA hydrogels and exhibited good proliferative properties and cellular activity. In addition, new chondrocytes and chondrogenic matrix, as well as type II collagen were observed after 8 weeks of implantation. At the same time, the transplanted auricle complex kept full and delicate auricle shape. This study demonstrates the potential of using 3D printing technology to construct in vitro living auricle tissue. It shows a great prospect in the clinical application of auricle regeneration.

3D printed titanium scaffolds with homogeneous diamond-like structures mimicking that of the osteocyte microenvironment and its bone regeneration study.

Biofabrication of personalized titanium scaffold mimicking that of the osteocyte microenvironment is challenging due to its complex geometrical cues. The effect of scaffolds geometrical cues and implantation sites on osteogenesis is still not clear. In this study, personalized titanium scaffolds with homogeneous diamond-like structures mimicking that of the osteocyte microenvironment were precisely designed and fabricated by selected laser melting method. The effects of different geometric cues, including porosity, pore sizes and interconnection properties, on cellular behavior were investigated. Biomimetic mechanical properties of porous titanium alloy scaffold were predesigned and simulated by finite element analysis.In vitroexperiment revealed that homogeneous diamond-like structures mimicking that of the osteocyte microenvironment triggered osteocyte adhesion and migration behavior. Typical implantation sites, including rabbit femur, beagle femur, and beagle skull, were used to study the implantation sites effects on bone regeneration.In vivoexperimental results indicated that different implantation sites showed significant differences. This study helps to understand the scaffolds geometrical microenvironment and implantation sites effects on osteogenesis mechanism. And it is beneficial to the development of bone implants with better bone regeneration ability.

[Mentocervical reconstruction and effectiveness evaluation in treatment of mentocervical cicatricial contracture deformity].

OBJECTIVE: To investigate the procedures and effectiveness of platysma scar flap for reconstructing mentocervical appearance in patients with mentocervical cicatricial contracture deformity. METHODS: Between April 2004 and August 2011, 26 patients with mentocervical cicatricial contracture deformities were admitted. There were 15 males and 11 females, aged 12-31 years (mean, 18 years). The causes included scald injury in 19 cases and flame injury in 7 cases, including 23 cases of deep second degree burn and 3 cases of third degree burn. The time between injury and scar formation was 6-27 months (mean, 10 months). The mentocervical angle was (117.10 +/- 14.46) degrees, and the cervicomental angle was (143.38 +/- 15.68) degrees. The platysma scar flap transfer (8 cm x 7 cm to 10 cm x 8 cm in size) and skin grafting were performed to reconstruct mentocervical appearance. RESULTS: The flap and skin graft all survived and the incisions healed by first intention. All the patients were followed up 6 months-3 years (mean, 16 months). The mentocervical and cervicomental angles were significantly reduced to (89.31 +/- 6.30) degrees and (117.83 +/- 10.65) degrees respectively at 2 weeks after operation (P < 0.05), showing no significant difference when compared with normal mentocervical angle (90 degrees) and cervicomental angle (120 degrees) (P > 0.05). The satisfactory results of the mentocervical appearance and cervical extension function were obtained in 21 patients whose mentocervical and cervicomental angles were restored to normal. CONCLUSION: Platysma scar flap transfer is an effective method to reconstruct mentocervical appearance and reduce mentocervical and cervicomental angles in patients with mentocervical cicatricial contracture deformity.