Peripheral nerve injuries can result in lifelong disability. Primary coaptation is the treatment of choice when the gap between transected nerve ends is short. Long nerve gaps seen in more complex injuries often require autologous nerve grafts or nerve conduits implemented into the repair. Nerve grafts, however, cause morbidity and functional loss at donor sites, which are limited in number. Nerve conduits, in turn, lack an internal scaffold to support and guide axonal regeneration, resulting in decreased efficacy over longer nerve gap lengths. By comparison, peptide amphiphiles (PAs) are molecules that can self-assemble into nanofibers, which can be aligned to mimic the native architecture of peripheral nerve. As such, they represent a potential substrate for use in a bioengineered nerve graft substitute. To examine this, we cultured Schwann cells with bioactive PAs (RGDS-PA, IKVAV-PA) to determine their ability to attach to and proliferate within the biomaterial. Next, we devised a PA construct for use in a peripheral nerve critical sized defect model. Rat sciatic nerve defects were created and reconstructed with autologous nerve, PLGA conduits filled with various forms of aligned PAs, or left unrepaired. Motor and sensory recovery were determined and compared among groups. Our results demonstrate that Schwann cells are able to adhere to and proliferate in aligned PA gels, with greater efficacy in bioactive PAs compared to the backbone-PA alone. In vivo testing revealed recovery of motor and sensory function in animals treated with conduit/PA constructs comparable to animals treated with autologous nerve grafts. Functional recovery in conduit/PA and autologous graft groups was significantly faster than in animals treated with empty PLGA conduits. Histological examinations also demonstrated increased axonal and Schwann cell regeneration within the reconstructed nerve gap in animals treated with conduit/PA constructs. These results indicate that PA nanofibers may represent a promising biomaterial for use in bioengineered peripheral nerve repair.

Background

Mobile device technology has revolutionized interpersonal communication, but the application of this technology to the physician-patient relationship remains limited due to concerns over patient confidentiality and the security of digital information. Nevertheless, there is a continued focus on improving communication between doctors and patients in all fields of medicine as a means of improving patient care. In this study, we implement a novel communications platform to demonstrate that instantaneously sharing perioperative information with surgical patients and members of their support networks can improve patient care and strengthen the physician-patient relationship.

Methods

423 consecutive patients scheduled to undergo elective surgical procedures were offered complimentary registration to a secure, web-based service designed to distribute perioperative updates to a group of recipients designated by each patient via Short Message Service (SMS) and/or email. Messages were created by attending surgeons and delivered instantaneously through the web-based platform. In the postoperative period, patients and their designated message recipients, as well as participating healthcare providers, were asked to complete a survey designed to assess their experience with the messaging system. Survey results were statistically analyzed to determine satisfaction rates.

Results

Of the qualifying 423 patients, 313 opted to enroll in the study. On average, patients selected a total of 3.5 recipients to receive perioperative updates. A total of 1,195 electronic messages were generated for distribution to designated recipients during the study period and delivered to recipients located around the world. There were no documented errors or failures in message delivery. Satisfaction surveys were completed by 190 users of the service (73 %). Respondents identified themselves as either patients (n = 48, 25.5 %), family/friends (n = 120, 63.8 %), or healthcare providers (n = 15, 12 %). Satisfaction with the service was high: 94.2 % of users "enjoyed this software" and and 94.2 % of family/friends "felt more connected to their loved ones during surgery." 92.5 % would "recommend their loved ones sign up for this service". Ninety percent of patients who completed the survey reported "an improved hospital experience".

Conclusion

Digital communications platforms can facilitate the immediate transfer of HIPAA-compliant data to patients and their designees. Such systems can greatly improve the level of communication between physicians, patients, and patients' families and caregivers. All types of users, including healthcare professionals, patients, and their loved ones, recorded high levels of satisfaction. Based on these observations, we conclude that mobile digital communications platforms represent a way to harness the power of social media to enhance patient care.

Accurate and early prediction of tissue viability is the most significant determinant of tissue flap survival in reconstructive surgery. Perturbation in tissue water content (TWC) is a generic component of the tissue response to such surgeries, and, therefore, may be an important diagnostic target for assessing the extent of flap viability in vivo. We have previously shown that reflective terahertz (THz) imaging, a non-ionizing technique, can generate spatially resolved maps of TWC in superficial soft tissues, such as cornea and wounds, on the order of minutes. Herein, we report the first in vivo pilot study to investigate the utility of reflective THz TWC imaging for early assessment of skin flap viability. We obtained longitudinal visible and reflective THz imagery comparing 3 bipedicled flaps (i.e. survival model) and 3 fully excised flaps (i.e. failure model) in the dorsal skin of rats over a postoperative period of 7 days. While visual differences between both models manifested 48 hr after surgery, statistically significant (p < 0.05, independent t-test) local differences in TWC contrast were evident in THz flap image sets as early as 24 hr. Excised flaps, histologically confirmed as necrotic, demonstrated a significant, yet localized, reduction in TWC in the flap region compared to non-traumatized skin. In contrast, bipedicled flaps, histologically verified as viable, displayed mostly uniform, unperturbed TWC across the flap tissue. These results indicate the practical potential of THz TWC sensing to accurately predict flap failure 24 hours earlier than clinical examination.

Attempts to minimize scarring remain among the most difficult challenges facing surgeons, despite the use of optimal wound closure techniques. Previously, we reported improved healing of dermal excisional wounds in circadian clock neuronal PAS domain 2 (Npas2)-null mice. In this study, we performed high-throughput drug screening to identify a compound that downregulates Npas2 activity. The hit compound (Dwn1) suppressed circadian Npas2 expression, increased murine dermal fibroblast cell migration, and decreased collagen synthesis in vitro. Based on the in vitro results, Dwn1 was topically applied to iatrogenic full-thickness dorsal cutaneous wounds in a murine model. The Dwn1-treated dermal wounds healed faster with favorable mechanical strength and developed less granulation tissue than the controls. The expression of type I collagen, Tgfβ1, and α-smooth muscle actin was significantly decreased in Dwn1-treated wounds, suggesting that hypertrophic scarring and myofibroblast differentiation are attenuated by Dwn1 treatment. NPAS2 may represent an important target for therapeutic approaches to optimal surgical wound management.