Graft Site Research Articles

De novo contrived three-in-one oriented graft molecule for high-performance GO nanofiltration membranes with ultra-low friction 2D nanochannels

The realistic application promotion of two-dimensional graphene oxide (GO) membranes is hampered by the trade-off between permeance and stability due to the mismatching nanochannel structure and wall chemistry enabled by the current decoration strategy. To address this, we de novo contrive a three-in-one oriented graft molecule, 1-(3-aminopropyl)-2,3-dimethylimidazolium bromide. In this compound, amino groups can reduce GO while acting as covalently grafting sites, thereby expanding the graphene region and decreasing the molecular transport resistance. Imidazolium cation moieties can interact with oxygen-containing groups of GO to enhance membranes’ anti-swelling ability. The whole molecules act as pillars to maintain the interlayer spacing. The modified GO (AIMGO) membranes show one-order-of-magnitude permeance improvements over GO membranes, with equally promising rejections. Furthermore, AIMGO membranes display ideal stability, remaining intact after 20-day water and ethanol immersion, unlike rapidly swollen GO membranes. AIMGO membranes are effective in the realistic pharmaceutical area achieving a separation factor of 9.8, with ethanol permeance of 513 L m−2 h−1 bar−1, which far exceeds the state-of-the-art polymeric membranes for drug purification. Herein, we highlight the rational combination of wide interlayer distance, low wall friction, and strong interlayer interactions to establish an efficient pathway for overcoming the permeance-stability trade-off in GO membranes and other two-dimensional membranes.

Investigating the Impact of Wound Edge Approximation with Skin Grafting on Hypertrophic Scar Reduction: A Randomized Controlled Clinical Trial.

In modern burn care, the focus extends beyond mere patient survival to encompass long-term functional and cosmetic outcomes. Research suggests that the technique and manner of suturing during skin grafting play a significant role in scar formation. This study aimed to explore the effectiveness of wound edge approximation with skin grafting compared to the conventional approach, where the graft edge exclusively interacts with the wound edge, in reducing hypertrophic scar development. Seventy-four burn unit patients eligible for grafting were randomly allocated into two groups: those receiving grafts with overlapping edges (Group A) and those receiving grafts with edges tailored to the burn wound (Group B). Evaluation of graft sites occurred immediately post-surgery and at 1 and 6 months post-operatively using the standardized Vancouver Scar Scale (VSS) administered by trained surgeons. The findings of this study revealed that there was no statistically significant difference between the two examined groups regarding the average duration of hospitalization and the mean thickness of wounds (P>0.05). Similarly, the mean scores for pain, vascular index, and pigmentation index immediately post-surgery, at 1 month, and 6 months later, as well as the scar height index and flexibility immediately and at 1 month post-surgery, and the Vancouver Scar Scale index at the study's conclusion, showed no significant variation between the two groups (P>0.05). However, at the 6-month follow-up, the mean scar height score (P=0.004) in the overlapping group and the mean flexibility score (P=0.017) in the non-overlapping group were significantly lower compared to the respective alternative group. This indicates a notable improvement in scar height and wound flexibility in the overlapping group over the non-overlapping group after 6 months.

Transplant Renal Vein Stenosis (TRVS) Managed with Percutaneous Endovascular Stenting: A Case Report

Transplant renal vein stenosis (TRVS) is a rare vascular complication of renal transplant that can masquerade findings of rejection and infection. We report a case who presented 2 years 9 months post-transplant with localized non-tender heaviness and fullness at the graft site with renal dysfunction. Initial ultrasonogram (USG) was suggestive of graft pyelonephritis with perinephric collection, though, there were no clinical features of infection and cultures came as sterile. Doppler revealed findings of TRVS, which was confirmed with a CT angiogram. Graft vein angioplasty restored the hemodynamics, but the patient again presented after 4 months with incidentally detected graft dysfunction. USG Doppler showed graft vein stenosis at the same site, which was managed with an elective renal vein angioplasty with stent placement.

Heterotopic ovarian transplantation instead hormonal replacement therapy after radical hysterectomy for cervical cancer: case report and review of literature.

Only a few case reports have described heterotopic ovarian tissue transplantation (OTT) with the only objective of restoring ovarian function. Case report and review of the literature forreporting cases of heterotopic OTT with the only aim of restoring ovarian endocrine function. In a cancer survivor woman with a history of hysterectomy and bilateral oophorectomy for cervical cancer and because she poorly tolerated hormone replacement therapy (HRT), we performed a heterotopic OTT in a pelvic subcutaneous "pocket" after an OT cryostorage of 17years. A cyclic ovarian endocrine function started 3months after OTT with an immediate patient self-described improvement of her quality of life. A second OTT was performed 19months after, due to hot flushes recurrence and FSH increase. Despite a cyclic endocrine function, progesterone levels have always been low, resulting in a relative hyperoestrogenism state. In the future, the indications of heterotopic OTT could be spread in alternative to HRT. However, our data suggest that the heterotopic graft environment is less favorable to corpus luteum development, and further studies are needed to assay the best site of heterotopic graft, the optimal number of ovarian cortexfragmentsto graft, and the potential risk of relapse in case of malignant residual disease.

The buccal plug: A technique for management of focal cicatricial entropion and trichiasis.

Cicatricial entropion can be challenging to manage, and surgery may lead to anterior lamellar and focal lash loss or tarsal scarring. We describe a surgical technique to address focal cicatricial entropion that avoids conjunctival incisions and minimizes changes to the aesthetic contour of the eyelid. Four patients underwent surgery with a square portion of the posterior row of eyelash follicles being excised anterior to the tarsus. A buccal mucous membrane graft was then harvested and inserted between the lamella. The plug served to recreate a mucosal membrane at the posterior reflection of the eyelid and separate the anterior and posterior lamella mechanically. With a mean follow-up of 5.16 months, no patients experienced regrowth of lashes at the graft site, and corneal irritation from aberrant eyelashes was abated. The buccal plug technique provides an aesthetically minded, less invasive approach to surgical management of localized entropion with trichiasis.

Reactive Oxygen Species Responsive Multifunctional Fusion Extracellular Nanovesicles: Prospective Treatments for Acute Heart Transplant Rejection.

Heart transplantation offers life-saving treatment for patients with end-stage heart failure; however, ischemia-reperfusion injury (IRI) and subsequent immune responses remain significant challenges. Current therapies primarily target adaptive immunity, with limited options available for addressing IRI and innate immune activation. Although plant-derived vesicle-like nanoparticles show promise in managing diseases, their application in organ transplantation complications is unexplored. Here, this work develops a novel reactive oxygen species (ROS)-responsive multifunctional fusion extracellular nanovesicles carrying rapamycin (FNVs@RAPA) to address early IRI and Ly6C+Ly6G- inflammatory macrophage-mediated rejection in heart transplantation. The FNVs comprise Exocarpium Citri grandis-derived extracellular nanovesicles with anti-inflammatory and antioxidant properties, and mesenchymal stem cell membrane-derived nanovesicles expressing calreticulin with macrophage-targeting ability. A novel ROS-responsive bio-orthogonal chemistry approach facilitates the active targeting delivery of FNVs@RAPA to the heart graft site, effectively alleviating IRI and promoting the polarization of Ly6C+Ly6G- inflammatory macrophages toward an anti-inflammatory phenotype. Hence, FNVs@RAPA represents a promising therapeutic approach for mitigating early transplantation complications and immune rejection. The fusion-targeted delivery strategy offers superior heart graft site enrichment and macrophage-specific targeting, promising improved transplant outcomes.

Mimicking Mytilus edulis foot protein: A versatile strategy for robust biomedical coatings

Universal coatings with versatile surface adhesion, good mechanochemical robustness, and the capacity for secondary modification are of great scientific interest. However, incorporating these advantages into a system is still a great challenge. Here, we report a series of catechol-decorated polyallylamines (CPAs), denoted as pseudo-Mytilus edulis foot protein 5 (pseudo-Mefp-5), that mimic not only the catechol and amine groups but also the backbone of Mefp-5. CPAs can fabricate highly adhesive, robust, multifunctional polyCPA (PCPA) coatings based on synergetic catechol-polyamine chemistry as universal building blocks. Due to the interpenetrating entangled network architectures, these coatings exhibit high chemical robustness against harsh conditions (HCl, pH 1; NaOH, pH 14; H2O2, 30%), good mechanical robustness, and wear resistance. In addition, PCPA coatings provide abundant grafting sites, enabling the fabrication of various functional surfaces through secondary modification. Furthermore, the versatility, multifaceted robustness, and scalability of PCPA coatings indicate their great potential for surface engineering, especially for withstanding harsh conditions in multipurpose biomedical applications.

Long-term histological and hemodynamic findings of repairing penile tunica albuginea defects with collagen fleece in dogs.

Clinically, collagen fleece patching of the penile tunica albuginea (TA) has been successful. However, the histopathological and hemodynamic outcomes are not known. We studied in vivo TachoSil® patching in two beagle dogs weighing 16.8 (16.7-16.9) Kg. Bilateral intracavernous pressures (ICP) response to 10 mg papaverine hydrochloride were measured. A full-thickness defect was created on the left side in TA 1 × 0.5 cm, and four transverse incisions 1 cm long were made on the right side, placed 0.5 cm apart, and covered with TachoSil®. Six months later, ICP measurements were repeated, and the penis was excised for histopathology. Grossly, the graft site was indistinguishable. The mean baseline ICP was 19.3 ± 2.98 mmHg and increased after papaverine injection to a mean peak ICP of 122 ± 26.1 mmHg. The ICP measurement before and after grafting did not show a significant difference in the baseline (p = 0.068) or the peak pressure (p = 0.465). Histologically, minimal foreign body reaction was seen, and the TA was completely regenerated. The underlying cavernous tissue did not show inflammation or necrosis. The study is the first to show the long-term histopathologic regeneration of TA after collagen fleece patching while maintaining the hemodynamic response to papaverine.

Highly efficient adsorption and removal of Cd(II) from wastewater by mass synthesis of magnetically functionalized UiO-66 based on its high coordination advantage

The development of heavy metal adsorbent materials that combine high yield and high adsorption capacity is a challenging problem. In this study, we report a novel magnetic adsorbent (Fe3O4@UiO-66-Lcys) for the efficient removal of cadmium from wastewater. Among them, UiO-66 was loaded on the Fe3O4 core by solvothermal method, followed by loading a large amount of L-cysteine (Lcys) on its surface by amidation reaction. The material innovatively achieves a large and uniform loading of functionalized groups on the magnetic core, which is a strategy for targeted removal of heavy metals. The successful synthesis of the materials was confirmed by structural characterization such as FTIR, TGA, and XRD. Excitingly, the composite has excellent adsorption performance, with the maximum adsorption of Cd2+ by Fe3O4@UiO-66-Lcys of 430.89 mg/g at the temperature of 298 K, which is more than five times that of Fe3O4@UiO-66. According to the mechanism analysis, the large amount of –COOH on UiO-66 provided enough sites for the stable grafting of L-cysteine, which exposed a large number of –NH2, –COOH, and −SH groups on the surface of the material, and provided abundant adsorption sites for Cd2+ chelation. In addition, the structure of the adsorbed material remained stable, and the removal rate of Cd2+ was still above 90 % after five times of reuse. Therefore, Fe3O4@UiO-66-Lcys is a good adsorbent for the removal of Cd2+ from wastewater, which provides an idea for the development and creation of high-yield, high-efficiency, and reusable green adsorbents.

Paraffinoma of the hands: a case report

Paraffin injection has been widely used to improve body contouring or to augment various body parts, although it has now been abandoned owing to serious complications. Paraffin injection may lead to complications after a long latency period, ranging from several years to several decades. Here, we present the rare case of a 77-year-old woman who suffered from recurrent wound problems after a bilateral paraffin injection into her hands 40 years ago. Initially, conservative debridement was carried out due to the patient’s reluctance to undergo extensive surgery and cost concerns. However, this resulted in recurrent wound dehiscence and infection. After serial debridement procedures, a skin graft was performed on her right hand. The patient complained of a depressed contour and numbness at the skin graft site, and tightness and discomfort of her right hand during flexion of the metacarpophalangeal joint. Three years later, the patient presented with a highly similar wound on her left hand. Thorough excision of the soft tissue infiltrated by paraffin was performed, followed by reconstruction using a sensate free anterolateral thigh flap. The patient responded well postoperatively without complications, displaying a fair range of motion without discomfort, sensory restoration of the flap, and satisfaction with the contour of the dorsum. This case report highlights the importance of complete excision of soft tissues infiltrated by paraffin for definitive treatment. Among the various reconstruction options, a sensate free flap is a good choice for achieving favorable functional and esthetic outcomes in hand reconstruction after radical excision of a paraffinoma.

Application of Human Acellular Dermal Matrix with Skin Graft for Lacunar Soft-Tissue Defect of Lateral Heel after Calcaneal Fracture.

To investigate the clinical effect of human acellular dermal matrix (HADM) combined with split-thickness skin graft in repairing lacunar soft tissue defects of the lateral heel after calcaneal fracture. From June 2018 to October 2020, providers repaired 11 cases of lacunar soft tissue defects at the lateral part of the heel using HADM combined with split-thickness skin graft. After thorough debridement, the HADM was trimmed and filled into the lacunar defect area. Once the wound was covered, a split-thickness skin graft and negative-pressure wound therapy were applied. Providers evaluated the appearance, scar, ductility of the skin graft site, appearance of the donor site, healing time, and any reoperation at follow-up. Of the 11 cases, 8 patients achieved successful wound healing by primary intention. Three patients showed partial necrosis in the edge of the skin graft, but the wound healed after standard wound care. Evaluation at 6 and 12 months after surgery showed that all patients had wound healing and mild local scarring; there was no obvious pigmentation or scar formation in the donor skin area. The average healing time was 37.5 days (range, 24-43 days). The HADM combined with split-thickness skin graft is a simple and effective reconstruction method for lacunar soft tissue defect of the lateral heel after calcaneal fracture. In this small sample, the combination demonstrated few infections, minor scar formation, few donor site complications, and relatively short hospital stays.

Optimizing Binding among Bimolecular Tethered Complexes.

Tethered motion is ubiquitous in nature, offering controlled movement and spatial constraints to otherwise chaotic systems. The enhanced functionality and practical utility of tethers has been exploited in biotechnology, catalyzing the design of novel biosensors and molecular assembly techniques. While notable technological advances incorporating tethered motifs have been made, a theoretical gap persists within the paradigm, hindering a comprehensive understanding of tethered-based technologies. In this work, we focus on the characterization of the binding kinetics of two tethered molecules functionalized to a hard surface. Using a mean-field approximation, the binding time of such bimolecular system is determined analytically. Furthermore, estimates of the grafting site separation and polymer lengths which expedite binding are provided. These estimates, along with the analytical theories and frameworks established here, have the potential to improve efficacy in self-assembly methods in DNA nanotechnology and can be extended to more biologically specific endeavors including targeted drug-delivery and molecular sensing.

Resorption Rates of Bone Graft Materials after Crestal Maxillary Sinus Floor Elevation and Its Influencing Factors.

The aim of this study is to analyze the resorption rate of bone graft materials after crestal sinus floor elevation, study its influencing factors, and improve the long-term success rate of implants after crestal maxillary sinus floor elevation. Measurement and analysis were conducted at six postoperative timepoints (0 months, 6 months, 12 months, 18 months, 24 months, and 30 months) using cone beam computed tomography (CBCT) data on 31 patients from the Chenghuaxinguanghua Dental Clinic who underwent crestal maxillary sinus floor elevation, involving 38 graft sites. The materials resorption rates of the bone graft height (BH) and bone graft width (BW) were assessed. BH and BW resorption rates followed the same trend (p = 0.07), with BH and BW resorption rates decreasing with time (rBH = -0.32, p < 0.01; rBW = -0.18, p < 0.01), and were maximal in the 0-6 month interval, with BH and BW resorption rates of 3.42%/mth and 3.03%/mth, respectively. The average monthly BH and BW resorption rates in the 6-12 month interval rapidly decreased to 1.75%/mth and 1.29%/mth, respectively. The monthly BH and BW resorption rates in the 12-30 month intervals stabilized at 1.45%/mth (p > 0.05) and 1.22%/mth (p > 0.05), respectively. The higher the initial bone graft height (BH0), the lower the BH resorption rates (rBH = -0.98, p < 0.05), and the BW resorption rate was different for different graft sites (p = 0.01). The resorption rates of bone graft materials implanted through crestal maxillary sinus floor elevation decreased rapidly within the first 12 months post operation and remained stable after 12 months. BH0 was identified as a significant factor influencing the resorption rates of bone graft materials. These results could suggest dentists should pay attention to the trend of resorption rates over time and carefully manage the initial height of bone grafts and inspire the research of new bone grafting materials for crestal maxillary sinus floor elevation.

Enhancement of Vascularization and Ovarian Follicle Survival Using Stem Cells in Cryopreserved Ovarian Tissue Transplantation-A Systematic Review.

The increase in cancer survival rates has put a focus on ensuring fertility preservation procedures for cancer patients. Ovarian tissue cryopreservation presents the only option for prepubertal girls and patients who require immediate start of treatment and, therefore, cannot undergo controlled ovarian stimulation. We aimed to provide an assessment of stem cells' impact on cryopreserved ovarian tissue grafts in regard to the expression of growth factors, angiogenesis promotion, tissue oxygenation, ovarian follicle survival and restoration of endocrine function. For this systematic review, we searched the Scopus and PubMed databases and included reports of trials using murine and/or human cryopreserved ovarian tissue for transplantation or in vitro culture in combination with mesenchymal stem cell administration to the grafting site. Of the 1201 articles identified, 10 met the criteria. The application of stem cells to the grafting site has been proven to support vascular promotion and thereby shorten the period of tissue hypoxia, which is reflected in the increased number of remaining viable follicles and faster recovery of ovarian endocrine function. Further research is needed before implementing the use of stem cells in OT cryopreservation and transplantation procedures in clinical practice. Complex ethical dilemmas make this process more difficult.

Drug Integrating Amphiphilic Nano-Assemblies: 2. Spatiotemporal Distribution within Inflammation Sites.

The need for chronic systemic immunosuppression, which is associated with unavoidable side-effects, greatly limits the applicability of allogeneic cell transplantation for regenerative medicine applications including pancreatic islet cell transplantation to restore insulin production in type 1 diabetes (T1D). Cell transplantation in confined sites enables the localized delivery of anti-inflammatory and immunomodulatory drugs to prevent graft loss by innate and adaptive immunity, providing an opportunity to achieve local effects while minimizing unwanted systemic side effects. Nanoparticles can provide the means to achieve the needed localized and sustained drug delivery either by graft targeting or co-implantation. Here, we evaluated the potential of our versatile platform of drug-integrating amphiphilic nanomaterial assemblies (DIANAs) for targeted drug delivery to an inflamed site model relevant for islet transplantation. We tested either passive targeting of intravenous administered spherical nanomicelles (nMIC; 20-25 nm diameter) or co-implantation of elongated nanofibrils (nFIB; 5 nm diameter and >1 μm length). To assess the ability of nMIC and nFIB to target an inflamed graft site, we used a lipophilic fluorescent cargo (DiD and DiR) and evaluated the in vivo biodistribution and cellular uptake in the graft site and other organs, including draining and non-draining lymph nodes, after systemic administration (nMIC) and/or graft co-transplantation (nFIB) in mice. Localized inflammation was generated either by using an LPS injection or by using biomaterial-coated islet-like bead implantation in the subcutaneous site. A cell transplant inflammation model was used as well to test nMIC- and nFIB-targeted biodistribution. We found that nMIC can reach the inflamed site after systemic administration, while nFIB remains localized for several days after co-implantation. We confirmed that DIANAs are taken up by different immune cell populations responsible for graft inflammation. Therefore, DIANA is a useful approach for targeted and/or localized delivery of immunomodulatory drugs to decrease innate and adaptive immune responses that cause graft loss after transplantation of therapeutic cells.

Total lower eyelid reconstructions with septal chondromucosal graft and pedicled flap on the superficial temporal artery

BackgroundSubtotal and total lower eyelid tissue loss after tumour excision is a complex issue for reconstructive surgeons. The anterior and posterior flaps must be restored to avoid compromising the functional and aesthetic prognosis of the eye. This study used a septal chondromucosal graft for the posterior lamella and a fasciocutaneous flap pedicled on the temporal artery for the anterior lamella. MethodWe conducted a 10-year monocentric retrospective study, including 18 patients who were treated using a septal chondromucosal graft with a temporal artery pedicle flap following tumour excision. We collected demographic and medico-surgical data related to flap survival, absence of ectropion, lagophthalmos and other post-operative complications. The aesthetic outcome was judged using a grading scale during the last follow-up consultation. ResultsAll grafts and flaps survived, whereas 2 patients required early repeat surgery (1 for ectropion and 1 for graft site haematoma). None of the patients developed lagophthalmos. Two patients had distal flap injuries that healed with local care. All patients were satisfied with the aesthetic outcome at the last follow-up visit. ConclusionCombining a septal chondromucosal graft with a fasciocutaneous flap pedicled to the temporal artery for total lower eyelid reconstruction is a reliable method with satisfactory functional and cosmetic outcomes.

Humeral Head Reconstruction of Reverse Hill-Sachs Lesions With Osteochondral Allograft

Background: True confirmed posterior shoulder dislocations are relatively uncommon injuries, with an estimated incidence of 1.1 per 100,000 individuals and are initially missed in up to 50% to 80% of cases. There are several treatment options for this injury presentation. In this case, we will focus on reconstruction with osteochondral allograft. Indications: If the cartilage cannot be fixed due to comminution or the cartilage is not viable due to chronicity or impact, osteochondral allograft might be a treatment option. This technique is typically considered for defects involving greater than 35% to 40% of the humeral head. Technique Description: The anterior defect on the humeral head was exposed on the cadaver specimen. Circular bone plugs were obtained from a distal femur specimen for grafting. Graft sites were prepared with a 15 reamer with an orthogonal approach to avoid oblique entry for a stacked bone plug configuration. Bone plug grafts were placed in the defect via press-fit fixation. The subscapularis is repaired to the lesser tubercle following the reconstruction. Results: Various studies reported improvement in pain, shoulder range of motion, and patient-reported outcome scores. A small percentage of patients developed allograft necrosis. Patients who received autografts had lower rates of osteoarthritis than patients who received allograft. Rehab protocol can last up to 12 months and begins with restricted range of motions and slowly advancing to isometric movements and gradually increasing range of motion and strengthening. Discussion/Conclusion: Outcomes described in previous studies are limited due to the low incidence of these injuries and small sample size. Missing the initial posterior dislocation as this is often correlated with inferior outcomes when treated in chronic setting. There is a risk of damage to humeral articular cartilage during osteochondral tissue harvesting so care must be taken during tissue harvest. Older, lower-demand patients have been reported to do well with nonoperative treatment, even in the case of a chronic dislocation, so careful discussion with the patient is needed to not perform surgery in a reasonably functioning non-painful shoulder. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

ACL Reconstruction with Peroneus Longus Autograft Using Endobutton &amp; Bioabsorbable Interference Screw and Brace Free Rehabilitation

Objective: To assess the functional outcome of arthroscopic anterior cruciate ligament (ACL) reconstruction with Peroneus longus tendon autografts using endobutton and interference screw at one-year follow-up post- operatively and brace-free rehabilitation. Material and Methods: A prospective study included 53 patients with clinical and radiological ACL deficiency. Arthroscopic ACL reconstruction was performed using Peroneus Longus double bundle autografts with sub- sequent brace-free rehabilitation. Pre- and postoperative assessment at one-year follow-up utilized the International Knee Documentation Committee (IKDC) score. Graft length and diameter were measured perioperatively, and donor site morbidity was evaluated using The American Orthopedic Foot and Ankle Score (AOFAS). Results: The study included 51 (94.4%) males and 2 (3.7%) females, mean age 27.3±7.2 years. Majority were left-sided procedures (64.8%). Peroneus Longus graft mean length and diameter were 116.8±5.3mm and 8.2±0.2mm respectively. At one-year follow-up, ankle joint movement at the graft site was preserved (mean AOFAS 98±0.8). There was a significant improvement in IKDC score postoperatively (p &lt; 0.05). Conclusions: ACL reconstruction with Peroneus longus autograft offers knee stability and facilitates early rehabilitation. Utilizing endobutton and bioabsorbable interference screw fixation supports graft strength until sufficient graft-to-bone healing occurs. Patients regain pre-injury activity levels, including stair climbing, sitting cross-legged, and squatting without difficulty.

533 Preliminary in Vivo and Atomic Force Microscopy Assessment of Uninjured Skin, Donor and Graft Sites

533 Preliminary in Vivo and Atomic Force Microscopy Assessment of Uninjured Skin, Donor and Graft Sites

The Effects of Local Treatment of PTH(1-34) and Whitlockite and Hydroxyapatite Graft to the Calvarial Defect in a Rat Osteoporosis Model.

With the aging population, there is a rising incidence of senile diseases, notably osteoporosis, marked by fractures, prolonged recovery, and elevated mortality rates, underscoring the urgency for effective treatments. In this study, we applied the method of absorbing parathyroid hormone (PTH), a treatment for osteoporosis, into graft materials. Two types of graft materials with different properties, whitlockite (WH) and hydroxyapatite (HAP), were used. After forming calvarial defects in osteoporotic rats, WH and HAP grafts were implanted, with PTH applied directly to the graft sites. Micro-CT analysis was employed to assess bone regeneration, while tissue sections were stained to elucidate the regeneration process and bone cell dynamics. The results showed that bone regeneration was higher in the grafts that were actively degraded by osteoclasts in the early stage of regeneration. When PTH was applied, osteoclast activity increased, leading to enhanced bone regeneration. Furthermore, the activation of osteoclasts resulted in the penetration and formation of new bone within the degraded graft, which exhibited higher osseointegration. Therefore, for osteoporotic bone defects, bone grafts that can be easily degraded by osteoclasts are more suitable. Additionally, treatment with PTH can activate osteoclasts around the bone graft in the early stages of regeneration, inducing higher bone regeneration and improving osseointegration.