Three-Dimensional Bioprinting Materials with Potential Application in Preprosthetic Surgery

Current methods in handling maxillofacial defects are not robust and are highly dependent on the surgeon’s skills and the inherent potential in the patients’ bodies for regenerating lost tissues. Employing custom-designed 3D printed scaffolds that securely and effectively reconstruct the defects by using tissue engineering and regenerative medicine techniques can revolutionize preprosthetic surgeries. Various polymers, ceramics, natural and synthetic bioplastics, proteins, biomolecules, living cells, and growth factors as well as their hybrid structures can be used in 3D printing of scaffolds, which are still under development by scientists. These scaffolds not only are beneficial due to their patient-specific design, but also may be able to prevent micromobility, make tension free soft tissue closure, and improve vascularity. In this manuscript, a review of materials employed in 3D bioprinting including bioceramics, biopolymers, composites, and metals is conducted. A discussion of the relevance of 3D bioprinting using these materials for craniofacial interventions is included as well as their potential to create analogs to craniofacial tissues, their benefits, limitations, and their application

Nanomagnetic-Mediated Drug Delivery for The Treatment of Dental Disease

Maintaining the vitality of the dental pulp, the highly innervated and highly vascular, innermost layer of the tooth, is a critical goal of any dental procedure. Upon injury, targeting the pulp with specific therapies is challenging because it is encased in hard tissues. This project describes a method that can effectively deliver therapeutic agents to the pulp. This method relies on the use of nanoparticles that can be actively steered using magnetic forces to the pulp, traveling through naturally occurring channels in the dentin (the middle layer of the tooth). This method can reduce the inflammation of injured pulp and improve the penetration of dental adhesives into dentin. Such a delivery method would be less expensive, and both less painful and less traumatic than existing therapeutic options available for treatment of injured dental pulp. This technique would be simple and could be readily translated to clinical use

Dental Applications of Natural-Origin Polymers in Hard and Soft Tissue Engineering

Clinical advances in the treatment of dentoalveolar defects continue to evolve with the introduction of new innovations in regenerative medicine and tissue bioengineering. Recent developments in tissue engineering are aimed at safely and effectively regenerating a damaged or necrotic area by replenishing its cells and increasing surrounding gene expression. Various techniques have successfully given rise to porous scaffolds being used by clinicians to treat the defect and initiate the repair process. Tissue reconstruction using bioengineered scaffolds is advantageous over traditional autografting, since it prevents the instigation of pain and donor site morbidity while ultimately creating both the environment and machinery needed to induce cell proliferation, migration, and reattachment within the affected area. This review article aims to describe and review the available literature regarding the regenerative capacity of natural polymers used for the treatment of dentoalveolar defects. The repair mechanisms, advantages of protein and polysaccharide derivatives, and the potential of stem cell therapy are discussed

Resilience through Entrepreneurial Storytelling in Extreme Contexts:A Case Study of a Pharmaceutical Company in the Palestinian Territory

This case presents how entrepreneurial storytelling assists entrepreneurs in attracting new investors, pursuing innovation and developing resilience in the Palestinian Territory. It also examines the role of entrepreneurial storytelling in eluding political crises and supporting the CEO's vision to adapt changes in the political environment. Moreover, this case explains how entrepreneurs respond to local competitors who operate in the same uncontrollable and unpredictable environment. The case is written based on three semi-structured interviews (total seven hours) with the Chief Executive Officer 1 of Pharmacare Pharmaceuticals Public Limited Company (PCP) 2: Mr Bassim Khoury (BK). PCP is the third Palestinian pharmaceutical company in terms of turnover in 2021, with more than 100 products and 330 employees, and is the first company in the Palestinian Territory to expand internationally in 22 countries

Encoding of Stimulus Frequency and Sensor Motion in the Posterior Medial Thalamic Nucleus

In all sensory systems, information is processed along several parallel streams. In the vibrissa-to-barrel cortex system, these include the lemniscal system and the lesser-known paralemniscal system. The posterior medial nucleus (POm) is the thalamic structure associated with the latter pathway. Previous studies suggested that POm response latencies are positively correlated with stimulation frequency and negatively correlated with response duration, providing a basis for a phase locked loop-temporal decoding of stimulus frequency. We tested this hypothesis by analyzing response latencies of POm neurons, in both awake and anesthetized rats, to vibrissae deflections at frequencies between 0.3 and 11 Hz. We found no significant, systematic correlation between stimulation frequency and the latency or duration of POm responses. We obtained similar findings from recording in awake rats, in rats under different anesthetics, and in anesthetized rats in which the reticular activating system was stimulated. These findings suggest that stimulus frequency is not reliably reflected in response latency of POm neurons. We also tested the hypothesis that POm neurons respond preferentially to sensor motion, that is, they respond to whisking in air, without contacts. We recorded from awake, head-restrained rats while monitoring vibrissae movements. All POm neurons responded to passive whisker deflections, but none responded to noncontact whisking. Thus like their counterparts in the trigeminal ganglion, POm neurons may not reliably encode whisking kinematics. These observations suggest that POm neurons might not faithfully encode vibrissae inputs to provide reliable information on vibrissae movements or contacts

The grimace scale reliably assesses chronic pain in a rodent model of trigeminal neuropathic pain

The limited success in translating basic science findings into effective pain management therapies reflects, in part, the difficulty in reliably assessing pain in experimental animals. This shortcoming is particularly acute in the field of chronic, ongoing pain. Quantitative analysis of facial expressions—the grimace score—was introduced as a promising tool, however, it is thought to reliably assess only pain of short or medium duration (minutes to hours). Here, we test the hypothesis that grimace scores are a reliable metric of ongoing neuropathic pain, by testing the prediction that chronic constriction injury of the infraorbital nerve (CCI-ION) will evoke significant increases in grimace scale scores. Mice and rats were subjected to CCI-ION, and tested for changes in mechanical hypersensitivity and in grimace scores, 10 or more days after surgery. Both rats and mice with CCI-ION had significantly higher grimace scores, and significantly lower thresholds for withdrawal from mechanical stimuli applied to the face, compared to sham-operated animals. Fentanyl reversed the changes in rat grimace scale scores, suggesting that these scores reflect pain perception. These findings validate the grimace scale as a reliable and sensitive metric for the assessment of ongoing pain in a rodent model of chronic, trigeminal neuropathic pain. Keywords: Chronic pain, Constriction nerve injury, Behavior, Pain metric

Amplified parabrachial nucleus activity in a rat model of trigeminal neuropathic pain

The parabrachial (PB) complex mediates both ascending nociceptive signaling and descending pain modulatory information in the affective/emotional pain pathway. We hypothesized that PB hyperactivity influences chronic pain behavior after trigeminal nerve injury in rats. Following induction of neuropathic pain using the chronic constriction injury of the infraorbital nerve (CCI-ION) model, rats displayed spontaneous markers of pain and mechanical hyperalgesia extending beyond the receptive field of the injured nerve. PB neurons recorded from rats with CCI-ION displayed amplified activity, manifesting as significantly longer responses to sensory stimuli, compared to shams. These findings suggest that chronic neuropathic pain involves PB hyperactivity. Keywords: Chronic pain, Affective pain, Facial grimace, Chronic constriction injury, After-discharge