ABSTRACT
Electrospun mats of PLA and PLA/Hap nanofibers produced by electrospinning were loaded with doxycycline (Doxy) through physical adsorption from a solution with initial concentrations of 3 g/L, 7 g/L, and 12 g/L, respectively. The morphological characterization of the produced material was performed using scanning electron microscopy (SEM). The release profiles of Doxy were studied in situ using the differential pulse voltammetry (DPV) electrochemical method on a glassy carbon electrode (GCE) and validated through UV-VIS spectrophotometric measurements. The DPV method has been shown to be a simple, rapid, and advantageous analytical technique for real-time measurements, allowing accurate kinetics to be established. The kinetics of the release profiles were compared using model-dependent and model-independent analyses. The diffusion-controlled mechanism of Doxy release from both types of fibers was confirmed by a good fit to the Korsmeyer-Peppas model.
ABSTRACT
The present study aimed to assess the in vitro antimicrobial effects of a novel biomaterial containing polylactic acid (PLA), nano-hydroxyapatite (nano-HAP) and Doxycycline (Doxy) obtained by electrospinning and designed for the non-surgical periodontal treatment. The antimicrobial activity of two samples (test sample, PLA-HAP-Doxy7: 5% PLA, nano-HAP, 7% Doxy and control sample, PLA-HAP: 5% PLA, nano-HAP) against two periodontal pathogensAggregatibacter actinomycetemcomitans and Porphyromonas gingivaliswas assessed using the Kirby−Bauer Disk Diffusion Susceptibility Test and compared with the effect of four antibiotics used as adjuvants in periodontal therapy: Amoxicillin, Ampicillin, Doxy and Metronidazole. The test sample (embedded with Doxy) showed higher inhibitory effects than commonly used antibiotics used in the treatment of periodontitis, while the control sample showed no inhibitory effects. Moreover, significant differences were observed between the inhibition zones of the two samples (p < 0.05). The Doxy-loaded PLA nanofibres had an antimicrobial effect against the periodontal pathogens. Based on these results, the novel biomaterial could be a promising candidate as adjuvant for the non-surgical local treatment in periodontitis.
ABSTRACT
The present study aimed to prepare nanofibers by electrospinning in the system polylactic acid-hydroxyapatite-doxycycline (PLA-HAP-Doxy) to be used as a drug delivery vehicle. Two different routes were employed for the preparation of Doxy-containing nanofibers: Immobilization on the electrospun mat's surface and encapsulation in the fiber structure. The nanofibers obtained by Doxy encapsulation were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric (TG) and differential thermal analyses (DTA) and scanning electron microscopy (SEM). The adsorption properties of pure PLA and PLA-HAP nanofibers were investigated for solutions with different Doxy concentrations (3, 7 and 12 wt%). Moreover, the desorption properties of the active substance were tested in two different fluids, simulated body fluid (SBF) and phosphate buffer solution (PBS), to evidence the drug release properties. In vitro drug release studies were performed and different drug release kinetics were assessed to confirm the use of these nanofiber materials as efficient drug delivery vehicles. The obtained results indicate that the PLA-HAP-Doxy is a promising system for biomedical applications, the samples with 3 and 7 wt% of Doxy-loaded PLA-HAP nanofibers prepared by physical adsorption are the most acceptable membranes to provide prolonged release in PBS/SBF rather than an immediate release of Doxy.
ABSTRACT
Objective: Identity recovery in people diagnosed with schizophrenia who have committed homicide poses several difficulties. Premorbid mental illnesses, the experience of psychosis, and the absence of cohesive ego functions may result in the inability to integrate the homicidal act into self-identity. Problems with integration increase the risk of recidivism and further mental problems. The aim of the present research was to explore how homicidal people diagnosed with schizophrenia make sense of their actions, and how they identify with the homicide. Method: Six semi-structured interviews were conducted at a long-term psychiatric home with people who had committed homicide and who had been diagnosed with schizophrenia. The interviews were transcribed verbatim and analysed using interpretative phenomenological analysis (IPA), an idiographic method rooted in phenomenologist traditions that focuses on how participants experience and make sense of events in their lives, and how those events affect their identity and sense of self. Results: Three personal experiential themes were established as a result of the analysis: (1) homicide and responsibility; (2) homicide and self; and (3) control over threats to self and self-evaluation. (1) Homicide was often reported to have been committed in a non-conscious, delusional state that may have led to the loss of self-determination. (2) Our interviewees struggled to integrate their acts into their identities. They distanced themselves from the crime or held multiple, parallel interpretations of the act. (3) Recovering patients experienced the constant threat of entering into a delusional reality and losing control. The importance of control was central to their self-evaluation. The patients appeared to distance themselves from the homicidal act and to regard their delusional selves as a threat to their lives. Conclusion: Therapy aimed at bolstering self-control, supporting the integration of the fragmented self, and raising awareness of the connections between delusional reality and standard, intersubjective reality may be helpful in reducing the instability of the self. Therapy aimed at processing complex grief and loss of family is also needed.
