Hyaluronic acid/platelet rich plasma-infused core-shell nanofiber membrane to prevent postoperative tendon adhesion and promote tendon healing.

An anti-adhesive barrier membrane incorporating hyaluronic acid (HA) can reduce fibroblasts attachment and impart lubrication effect for smooth tendon gliding during management of post-surgical tendon adhesion. On the other hand, as numerous growth factors are required during tendon recovery, growth factors released by platelets in platelet-rich plasma (PRP) can provide beneficial therapeutic effects to facilitate tendon recovery post tendon injury. Furthermore, PRP is reported to be associated with anti-inflammatory properties for suppressing postoperative adhesion. Toward this end, we fabricate core-shell nanofiber membranes (NFM) with HA/PRP-infused core and polycaprolactone shell in this study. Different NFM with 100 % (H-P), 75 % (HP31-P), 50 % (HP11-P) and 25 % (H31-P) HA in the core was fabricated through coaxial electrospinning and analyzed through microscopic, pore size, mechanical, as well as HA and growth factor release studies. In vitro study with fibroblasts indicates the NFM can act as a barrier to prevent cell penetration and reduce cell attachment/focal adhesion, in addition to promoting tenocyte migration in tendon healing. In vivo studies in a rabbit flexor tendon rupture model indicates the HP11-P NFM shows improved efficacy over H-P NFM and control in reducing tendon adhesion formation and inflammation, while promoting tendon healing, from functional assays and histological analysis.

Quantified Facial Rejuvenation Utilizing High Intense Focus Ultrasound with Multiple Penetrative Depths.

Background: Multiple penetration depths of high-intensity focused ultrasound (HIFU) treatment for facial rejuvenation have not been quantified. Methods: We enrolled 12 participants (n=24) to undergo one session of HIFU rejuvenation between January 1, 2019, and January 10, 2020. We used a 2-, 4.5-, and 6-mm focal depth transducer on the upper and middle face. We evaluated efficacy on days 60 and 90 by using our specific assessment system. Results: The average eyebrow peak and pupil-eyebrow peak angles significantly increased by 2° (p < 0.0005) and decreased by 1° (p < 0.0001), respectively, at day 90. The shortened eyebrow-iris length indicated that the forehead tissues had lifted and moved medially to the central face. Supraorbital tissues were also vertically elevated, marked by the eyebrow-orbital (p = 0.0016) and vertical palpebral fissure lengths (p = 0.0052), which both exhibited a 0.8-cm elevation. For the midface, the increased canthus-oral-nasal angle (p = 0.5881) and decreased tragus-oral length (p = 0.5881) indicated that laxity had been corrected through lifted oral commissure, though the data were not statistically significant. No serious side effects were observed. Conclusion: HIFU treatment with multiple depths quantitatively improved both upper-facial rejuvenation and midface rejuvenation after a single session.

Cephalometric analysis following combined Sub-SMAS hyaluronic acid injection and subdermal and supraperiosteal poly-L-lactic acid injections in Asian women.

BACKGROUND: The aging face is characterized by skin laxity and volume loss. Attenuation of facial retaining ligaments significantly contributes to skin sagginess and soft tissue volume loss. AIMS: We designed a prospective cohort study to quantitatively assess the efficacy of hyaluronic acid (HA) with adjunct poly-L-lactic acid (PLLA) injections in strengthening the retaining ligaments. PATIENTS/METHODS: A total of 12 Asian women were treated with HA injections to the orbital, zygomatic, buccal-maxillary, and mandibular retaining ligaments with adjunct supraperiosteal and subdermal PLLA injections to the temporal region, midface, and lower face. Cephalometric measurements were done before treatment and 2, 4, 12, and 24 weeks post-procedurally. RESULTS: Eyebrow peak and tail angles increased 20.0° ± 3.8° to 21.0° ± 3.8° (p < 0.05) and -2.9° ± 4.2° to -1.3° ± 3.3° (p < 0.001) at week 12. Eyebrow-to-orbital-rim distance increased 1.9 ± 2.0 mm to 3.9 ± 1.5 mm (p < 0.001) at week 12. Eyebrow-to-upper-eyelid distance increased 11.6 ± 3.0 mm to 12.7 ± 3.2 mm (p < 0.001) at week 24. Eyebrow-peak-to-lateral-limbus distance decreased 6.1 ± 3.1 mm to 5.3 ± 2.4 mm (p < 0.05) at week 4. Tragus-oral-commissure length and lower-facial-contouring length decreased 281 ± 11 mm to 275 ± 10 mm (p < 0.01) and 297 ± 14 to 292 ± 11 mm (p < 0.05) at week 12, respectively. CONCLUSION: Hyaluronic acid injection for strengthening of facial retaining ligaments with adjunct PLLA is viable, safe, and effective in facial rejuvenation as supported by quantitative data.

Shock Index as a Predictor for Angiographic Hemostasis in Life-Threatening Traumatic Oronasal Bleeding.

The objective of this retrospective study was to identify predictors of angiographic hemostasis among patients with life-threatening traumatic oronasal bleeding (ONB) and determine the threshold for timely referral or intervention. The diagnosis of traumatic, life-threatening ONB was made if the patient suffered from craniofacial trauma presenting at triage with unstable hemodynamics or required a definitive airway due to ONB, without other major bleeding identified. There were 4404 craniofacial trauma patients between January 2015 and December 2019, of which 72 (1.6%) fulfilled the diagnosis of traumatic life-threatening ONB. Of these patients, 39 (54.2%) received trans-arterial embolization (TAE), 11 (15.3%) were treated with other methods, and 22 (30.5%) were excluded. Motor vehicle accidents were the most common cause of life-threatening ONB (52%), and the internal maxillary artery was the most commonly identified hemorrhaging artery requiring embolization (84%). Shock index (SI) was significantly higher in the angiographic hemostasis group (p < 0.001). The AUC-ROC was 0.87 (95% CI, 0.88-1.00) for SI to predict angiographic hemostasis. Early recognition and timely intervention are crucial in post-traumatic, life-threatening ONB management. Patients initially presenting with SI > 0.95 were more likely to receive TAE, with the TAE group having statistically higher SI than the non-TAE group whilst receiving significantly more packed red blood cells. Hence, for patients presenting with life-threatening traumatic ONB and a SI > 0.95, TAE should be considered if preliminary attempts at hemostasis have failed.

Tension Stimulation of Tenocytes in Aligned Hyaluronic Acid/Platelet-Rich Plasma-Polycaprolactone Core-Sheath Nanofiber Membrane Scaffold for Tendon Tissue Engineering.

To recreate the in vivo niche for tendon tissue engineering in vitro, the characteristics of tendon tissue underlines the use of biochemical and biophysical cues during tenocyte culture. Herein, we prepare core-sheath nanofibers with polycaprolactone (PCL) sheath for mechanical support and hyaluronic acid (HA)/platelet-rich plasma (PRP) core for growth factor delivery. Three types of core-sheath nanofiber membrane scaffolds (CSNMS), consisting of random HA-PCL nanofibers (Random), random HA/PRP-PCL nanofibers (Random+) or aligned HA/PRP-PCL (Align+) nanofibers, were used to study response of rabbit tenocytes to biochemical (PRP) and biophysical (fiber alignment) stimulation. The core-sheath structures as well as other pertinent properties of CSNMS have been characterized, with Align+ showing the best mechanical properties. The unidirectional growth of tenocytes, as induced by aligned fiber topography, was confirmed from cell morphology and cytoskeleton expression. The combined effects of PRP and fiber alignment in Align+ CSNMS lead to enhanced cell proliferation rates, as well as upregulated gene expression and marker protein synthesis. Another biophysical cue on tenocytes was introduced by dynamic culture of tenocyte-seeded Align+ in a bioreactor with cyclic tension stimulation. Augmented by this biophysical beacon from mechanical loading, dynamic cell culture could shorten the time for tendon maturation in vitro, with improved cell proliferation rates and tenogenic phenotype maintenance, compared to static culture. Therefore, we successfully demonstrate how combined use of biochemical/topographical cues as well as mechanical stimulation could ameliorate cellular response of tenocytes in CSNMS, which can provide a functional in vitro environmental niche for tendon tissue engineering.

Functional Hyaluronic Acid-Polylactic Acid/Silver Nanoparticles Core-Sheath Nanofiber Membranes for Prevention of Post-Operative Tendon Adhesion.

In this study, we prepared core-sheath nanofiber membranes (CSNFMs) with silver nanoparticles (Ag NPs) embedding in the polylactic acid (PLA) nanofiber sheath and hyaluronic acid (HA) in the nanofiber core. The PLA/Ag NPs sheath provides mechanical support as well as anti-bacterial and anti-inflammatory properties. The controlled release of HA from the core could exert anti-adhesion effects to promote tendon sliding while reducing fibroblast attachment. From the microfibrous structural nature of CSNFMs, they function as barrier membranes to reduce fibroblast penetration without hampering nutrient transports to prevent post-operative peritendinous adhesion. As the anti-adhesion efficacy will depend on release rate of HA from the core as well as Ag NP from the sheath, we fabricated CSNFMs of comparable fiber diameter, but with thick (Tk) or thin (Tn) sheath. Similar CSNFMs with thick (Tk+) and thin (Tn+) sheath but with embedded Ag NPs in the sheath were also prepared. The physico-chemical properties of the barrier membranes were characterized in details, together with their biological response including cell penetration, cell attachment and proliferation, and cytotoxicity. Peritendinous anti-adhesion models in rabbits were used to test the efficacy of CSNFMs as anti-adhesion barriers, from gross observation, histology, and biomechanical tests. Overall, the CSNFM with thin-sheath and Ag NPs (Tn+) shows antibacterial activity with low cytotoxicity, prevents fibroblast penetration, and exerts the highest efficacy in reducing fibroblast attachment in vitro. From in vivo studies, the Tn+ membrane also shows significant improvement in preventing peritendinous adhesions as well as anti-inflammatory efficacy, compared with Tk and Tn CSNFMs and a commercial adhesion barrier film (SurgiWrap®) made from PLA.