Polymeric Implants Research Articles

Cranial reconstruction utilizing polymeric implants in two different designs: finite element investigation

IntroductionImpact loads applied to the human head can result in skull fractures or other injuries that require a craniectomy. The removed portion is replaced with biological or synthetic materials using cranioplasty surgery. Titanium has been the material of choice for cranial implants due to its superior properties and biocompatibility; however, its issues have prompted the search for substitute materials (e.g., polymers). The issues are related to the requirement for surface modification, casting, radiologic incompatibility and potential allergy risks. Recently, polymeric materials have been used in many fields as alternatives to titanium.ObjectiveThis research aims to conduct a finite element study to evaluate the skull reconstruction process by using PEEK and carbon fiber reinforced PEEK 30 and 60% in the production of cranial implants as alternatives to conventional titanium implants.Materials and methodsA three-dimensional model of a defective skull was rehabilitated with a custom-made cranial implant. The implants were stimulated using two designs (plate and mesh), and different polymeric materials (PEEK and carbon fiber reinforced PEEK 30 and 60%) as titanium substitutes, under 2000 N impact force.ResultsThe results illustrated that plate implants reduced the stresses on the skull and increased the stresses on brain tissues compared to mesh implants. Titanium, CFR-PEEK 30 & 60% implants (whether mesh or flat) were not prone to fracture, unlike mesh PEEK implants. In addition, CFR-PEEK 60% implants produced the lowest values of stress, strain, and total deformation on the skull and brain compared to titanium implants, unlike PEEK implants. By using the titanium plate implant, the peak tensile and compressive stresses on the skull were 24.99 and 25.88 MPa, respectively. These stresses decreased to 21.6 and 24.24 MPa when using CFR-PEEK 60%, increased to 26.07 and 28.99 MPa with CFR-PEEK 30%, and significantly increased to 41.68 and 87.61 MPa with PEEK. When the titanium mesh implant was used, the peak tensile and compressive stresses on the skull were 29.83 and 33.86 MPa. With CFR-PEEK 60%, these stresses decreased to 27.77 and 30.57 MPa, and with CFR-PEEK 30% and PEEK, the stresses increased to 34.04 and 38.43 MPa, and 44.65 and 125.67 MPa, respectively. For the brain, using the titanium plate implant resulted in peak tensile and compressive stresses of 14.9 and 16.6 Pa. These stresses decreased to 13.7 and 15.2 Pa with CFR-PEEK 60%, and increased to 16.3 and 18.1 Pa, and 73.5 and 80 Pa, with CFR-PEEK 30% and PEEK, respectively. With the titanium mesh implant, the peak tensile and compressive stresses were 12.3 and 13.5 Pa. Using CFR-PEEK 60%, these stresses decreased to 11.2 and 12.4 Pa on the brain, and increased with CFR-PEEK 30% and PEEK to 14.1 and 15.5 Pa, and 53.7 and 62 Pa, respectively. Additionally, the contact area between the PEEK implant (whether mesh or plate design) and the left parietal bone of the skull was expected to be damaged due to excessive strains. Importantly, all implants tested did not exceed permissible limits for tensile and compressive stresses and strains on the brain.ConclusionIt was concluded that carbon fiber-reinforced PEEK implants, with 30% and 60% reinforcements, can be used as alternatives to titanium for cranial reconstruction. The addition of carbon fibers to the PEEK matrix in these percentages enhances the mechanical, chemical, and thermal properties of the implants. Additionally, these composites are characterized by their low weight, biocompatibility, lack of clinical issues, and ease of fabrication. They can also help preserve the skull, protect the brain, and are not susceptible to damage.Clinical significanceOvercoming the drawbacks of titanium cranial implants and increasing the effectiveness of the cranioplasty process by utilizing PEEK and carbon fiber reinforced PEEK materials in the reconstruction of the damaged portion of skull.

In Vivo Study of Organ and Tissue Stability According to the Types of Bioresorbable Bone Screws.

Biodegradable material, such as magnesium alloy or polylactic acid (PLA), is a promising candidate for orthopedic surgery. The alloying of metals and the addition of rare earths to increase mechanical strength are still questionable in terms of biosafety as absorbent materials. Therefore, the purpose of this study is to understand the effect of substances due to the degradation of various biodegradable substances on organs in the body or surrounding tissues. A total of eighty male Sprague-Dawley rats were selected for this study, and the animals were divided into four groups. Each of the three experimental groups was implanted with magnesium alloy, polymer, and titanium implants; the control group only drilled into the cortical bone. Serum assay, micro-CT, hematoxylin and eosin staining, immunoblotting, and real-time PCR were evaluated. There was no significant difference between the two groups of magnesium alloy and polymer in serum assay, but micro-CT analysis confirmed that magnesium alloy degrades faster than polymer, and histological examination showed a strong inflammatory response in the early stages, which was similarly observed in immunoblotting and real-time PCR. Our findings show that there was no toxicity due to the degradation of the biodegradable material, and the difference in each inflammatory response is thought to be determined by the rate of degradation in the body.

Multi-Layered Implant Approach for Hemilaryngectomy Reconstruction in a Porcine Model.

Partial laryngectomies result in voice, swallowing, and airway impairment for thousands of patients in the United States each year. Treatment options for dynamic restoration of laryngeal function are limited. Thus, there is a need for new reconstructive approaches. Here, we evaluated early (4 week) outcomes of multi-layered mucosal-myochondral (MMC) implants when used to restore laryngeal form and function after hemilaryngectomy in a porcine model. Six Yucatan minipigs underwent transmural hemilaryngectomies followed by reconstruction with customized MMC implants aiming to provide site-appropriate localization of regenerated laryngeal tissues, while supporting laryngeal function. All implants were fabricated from polymeric collagen, with a subset of muscle and cartilage implants containing motor endplate-expressing muscle progenitor cells or cartilage-like cells differentiated from adipose stem cells, respectively. Vocalization and laryngeal electromyography (L-EMG) measurements with nerve conduction studies were performed post-operatively and compared with baseline along with gross and histological analyses of the healing response. All animals (n = 6) survived and maintained airway patency, safe swallowing, and phonation, without the use of tracheostomy and/or gastrostomy tubes. Histological evaluation indicated no adverse tissue reaction or implant degradation, showing progressive regenerative remodeling with mucosa reformation and ingrowth of new muscle and cartilage. Preliminary L-EMG suggested weak but detectable motor unit action potentials. Although vocalization duration, frequency, and intensity decreased post-operatively, all animals retained vocal capacity and parameter recovery was evident over the study duration. Engineered collagen polymeric implants in the presence or absence of autologous cell populations may serve as a feasible reconstructive option to restore dynamic function after hemilaryngectomy. Long-term follow-up is needed to further assess functional outcomes. NA Laryngoscope, 2024.

“Janus” PEEK implant with sandwich Mg-containing coating for infected tissue repair

Having good antibacterial properties and promoting soft and hard tissue repair are the keys to successful implantation of intraosseous transcutaneous. Polyether ether ketone (PEEK) is a class of FDA-approved polymer implants. However, the surface of PEEK is bioinert, which is easy to cause postoperative infection and poor tissue integration. In this study, polypyrrole (Ppy) was polymerized on sulfonated PEEK, Mg3(PO4)2 nanosheets were grown in situ on one side, and polycaprolactone (PCL) was then spun on the surface to form a Janus-like surface on PEEK. The Ppy/Mg3(PO4)2/PCL composite coating could inhibit bacterial adhesion, and the excellent photothermal properties of Ppy/Mg3(PO4)2/PCL and Ppy coatings further promote the removal of bacteria due to the accumulated heat. After the infection was eliminated, the Janus-like surface of modified PEEK switched macrophages to anti-proinflammatory response and promoted both soft and hard tissue repair. The Ppy modified sulfonated PEEK could promote collagen secretion in the soft tissue, while the PCL films on Ppy/Mg3(PO4)2/PCL was densified by temperature response under near-infrared light treatment to close the exposed interface of Mg3(PO4)2 nanosheets that was more conducive to bone repair. In summary, PEEK with Janus-like surface consisting of Ppy/Mg3(PO4)2/PCL and Ppy has multiple biological functions of sequential antibacterial and soft and hard tissue repair, and is a promising candidate material for intraosseous transcutaneous implants.

A Systematic Review of the Contribution of Additive Manufacturing toward Orthopedic Applications.

Human bone holds an inherent capacity for repairing itself from trauma and damage, but concerning the severity of the defect, the choice of implant placement is a must. Additive manufacturing has become an elite option due to its various specifications such as patient-specific custom development of implants and its easy fabrication rather than the conventional methods used over the years. Additive manufacturing allows customization of the pore size, porosity, various mechanical properties, and complex structure design and formulation. Selective laser melting, powder bed fusion, electron beam melting, and fused deposition modeling are the various AM methods used extensively for implant fabrication. Metals, polymers, biocrystals, composites, and bio-HEA materials are used for implant fabrication for various applications. A wide variety of polymer implants are fabricated using additive manufacturing for nonload-bearing applications, and β-tricalcium phosphate, hydroxyapatite, bioactive glass, etc. are mainly used as ceramic materials in additive manufacturing due to the biological properties that could be imparted by the latter. For decades metals have played a major role in implant fabrication, and additive manufacturing of metals provides an easy approach to implant fabrication with augmented qualities. Various challenges and setbacks faced in the fabrication need postprocessing such as sintering, coating, surface polishing, etc. The emergence of bio-HEA materials, printing of shape memory implants, and five-dimensional printing are the trends of the era in additive manufacturing.

Application of hs-CRP in Assessment of Tissue Inflammation Following Implantation of Biodegradable Polymer in Experiment.

Implants made of biodegradable polymers are replaced by regenerating tissues through inflammation. The changes occurring in tissues and the organism are of practical interest for studying the biocompatibility of the material and searching for systemic markers in the blood that reflect inflammation in peri-implantation tissues. The highly sensitive C-reactive protein (hs-CRP) measurements in blood and morphometric studies of tissue surrounding the implant were carried out in the experiment within three months of implantation of a biopolymer consisting of polycaprolactone (PCL) and polytrimethylene carbonate (PTMC). During the first month, tissue inflammation decreased, and the blood level of hs-CRP did not increase. The polymer biotransformation began in the tissues after a month of implantation and was accompanied by inflammation moving deeper into the matrix. Proliferation of inflammatory cells in tissues was reflected in an increase in the hs-CRP level three months after polymer installation. The result achieved confirmed the polymer's bioinertness. The level of hs-CRP in the blood of the animals correlated with the level of inflammation in peri-implantation tissues, reflecting the activity of inflammation in the process of polymer biotransformation. This inflammation protein can be recommended for assessing tissue processes following implantation of biopolymers and their biocompatibility.

A 3D printing-based hybrid manufacturing method for high-strength polymeric medical implant fabrication

This paper presents a novel 3D printing-based hybrid manufacturing method to fabricate high-strength polymeric medical implants. Poly-ether-ether-ketone (PEEK) and polyether sulfone (PES) are blended to make filament for use with the fused filament fabrication technique to print custom designed implants. After printing and annealing, PES is removed by leaching to create interconnected porous PEEK structure with suitable pore size and porosity for bone tissue ingrowth. The proposed method provides a versatile approach to fabricating medical implants that are both mechanically strong and microstructurally inducive to osseointegration. The polymeric implants are also X-ray transparent to allow post-surgery evaluations using an imaging method. An intervertebral spacer implant example is used to demonstrate the proposed fabrication method.

Determination of biodegradation performance for fabricated by MEW Chitosan/PCL composite stents with in vitro tests

Today, biodegradable implants have begun to become a serious alternative to permanent implant groups. Especially the development of polymer material technology can be an alternative to metallic medical instruments. An innovative manufacturing method for the fabricated of these polymeric implants is melt electrowriting (MEW). This innovative method, which emerged as a result of studies on the production quality of additive manufacturing technology, is used in products with smaller and more complex geometries, such as stents. It is anticipated that this method, which is particularly convenient for patient-specific implant models, will have an important place in the implant production market in the future. Within the framework of this perspective, in this study, a study was conducted on the polycarbolactone group using the MEW method. In order to improve the biodegradability character, biodegradability experiments of chitosan-doped stents were conducted in vitro. The degradation character of the samples subjected to immersion corrosion in two different media for 1, 7, 14 and 21 days was examined based on residual mass. It has been determined that chitosan reinforcement has a buffering effect and plays a retarding role on the degradation time.

Influence of Conditions for Obtaining Polylactide-Based Materials on Their Physico-Mechanical and Rheological Characteristics

The work is devoted to the study of the influence of the conditions for obtaining materials based on the synthetic polymer polylactide on their physico-mechanical and rheological characteristics. These materials are promising for the creation of biodegradable polymer implants of temporary action to maintain the mechanical properties of broken bones during the healing period. They are designed to replace the titanium fixators currently used for these purposes, which is due not only to the need for repeated surgery to extract them, but also to the fact that the strength and modulus of elasticity of titanium fixators exceed the values of bone strength indicators by an order of magnitude, which can cause the phenomenon of bone resorption and a decrease in its strength. It has been established that with an increase in temperature in the plasticization and pressing zone, as well as with an increase in pressure in the press, there is a natural decrease in the viscosity of the polylactide melt, as well as the values of the elastic modulus and breaking stress of solid samples. Varying the cooling rate of the material during the pressing process affects the degree of its crystallinity. At the same time, the lower the cooling rate, the greater the degree of crystallinity of the polylactide and the greater the values of the elastic modulus and breaking stress.

Novel dissolution methods for drug release testing of Long-Acting injectables

Long-acting parenteral drug products are a popular choice for therapeutic areas requiring long term treatment. These products range from dispersed systems such as drug suspensions and polymeric microspheres to in situ forming polymeric implants. The lack of reliable drug release testing methods for these drug products not only impedes the development of new drug products but also affects generic drug development. Current release methods suffer from a range of problems such as high variability, poor reproducibility, poor discriminatory ability, lack of depot-like structure formation (that could mimic the in vivo situation). Moreover, shorter duration (less than a week) of release renders them unsuitable for in vitro-in vivo correlations (IVIVCs). To overcome these issues, novel adapters were developed for both USP-type-II & IV apparatus. These adapters were validated and assessed using the long-acting injectable (LAI) suspension drug product Depo Provera 150® as well as its Q1/Q2 equivalents. For USP-type-IV apparatus, two open adapter designs (conical and ellipsoidal shaped cavity with volume capacities of 50 µl and 1 ml, respectively) were developed. A closed conical adapter design with a volume capacity of 0.05 ml was developed for USP apparatus type-II. All three novel adapter designs effectively retained the suspensions, achieved release durations of 3–6 weeks with good reproducibility, minimal variability (RSD≤5%) and had good discriminatory ability. Based on this, the adapter-based dissolution methods were deemed suitable for IVIVC development of long-acting injectables. A successful Level A IVIVC was developed for Depo SubQ Provera 104® and its Q1Q2 equivalents using USP apparatus type IV with a conical adapter design. The closed adapter design for apparatus type-II was also investigated for suitability with risperidone in situ forming implants. The adapter was able to securely retain and maintain the shape of the in situ forming implants and resulted in release profiles of up to one month with good discriminatory ability and low standard error (RSD≤5%). These novel adapters hold promise of wide use for in vitro release testing of different long-acting parenteral drug products.

Design and evaluation of mechanical strength of multi-material polymeric implants for mandibular reconstruction.

Reconstruction of mandible implants to address segmental abnormalities is still a challenging task, both in vitro and in vivo. The mechanical strength of the materials used is a critical factor that determines how well bone is regenerated. The reconstruction technique of mandibular abnormalities widely uses polymeric implants. It is critical to evaluate the mechanical resilience under different load cases, including axial, combined, and flexural loading conditions. This study developed implants for mandibular defects using a combination of four materials: polylactic acid (PLA), polyethylene terephthalate glycol (PETG), thermoplastic polyurethane (TPU), and polycaprolactone (PCL), with the aim of mimicking the inherent characteristics of cortical and cancellous bone structures and evaluating their mechanical properties to support bone Osseo integration. The eleven of these combinations of structures result below the micro strain threshold level of <3000 µε, and the five combinations of the structures result in micro strain above the threshold value. The intact bone study results show that the stress under axial, combined, and flexural loading conditions is 27.6, 38.9, and 64.9 MPa, respectively. This study's stress results are lower than those from the intact bone study. The study found that the combinations of PLA and TPU material were most preferred for the cortical and cancellous bone regions of polymeric implants. These materials are also compatible with 3D printing. The results of this study can be used to find multi-material combinations that are strong and flexible.

Customizable, biocompatible implants for dorsal nasal augmentation: An in vivo pilot study of eight polylactic acid scaffold designs.

Augmentation of the nasal dorsum often requires implantation of structural material. Existing methods include autologous, cadaveric or alloplastic materials and injectable hydrogels. Each of these options is associated with considerable limitations. There is an ongoing need for precise and versatile implants that produce long-lasting craniofacial augmentation. Four separate polylactic acid (PLA) dorsal nasal implant designs were 3D-printed. Two implants had internal PLA rebar of differing porosities and two were designed as "shells" of differing porosities. Shell designs were implanted without infill or with either minced or zested processed decellularized ovine cartilage infill to serve as a "biologic rebar", yielding eight total treatment groups. Scaffolds were implanted heterotopically on rat dorsa (N = 4 implants per rat) for explant after 3, 6, and 12 months followed by volumetric, histopathologic, and biomechanical analysis. Low porosity implants with either minced cartilage or PLA rebar infill had superior volume retention across all timepoints. Overall, histopathologic and immunohistochemical analysis showed a resolving inflammatory response with an M1/M2 ratio consistently favoring tissue regeneration over the study course. However, xenograft cartilage showed areas of degradation and pro-inflammatory infiltrate contributing to volume and contour loss over time. Biomechanical analysis revealed all constructs had equilibrium and instantaneous moduli higher than human septal cartilage controls. Biocompatible, degradable polymer implants can induce healthy neotissue ingrowth resulting in guided soft tissue augmentation and offer a simple, customizable and clinically-translatable alternative to existing craniofacial soft tissue augmentation materials. PLA-only implants may be superior to combination PLA and xenograft implants due to contour irregularities associated with cartilage degradation.

Computed tomography technologies to measure key structural features of polymeric biomedical implants from bench to bedside.

Implanted polymeric devices, designed to encourage tissue regeneration, require porosity. However, characterizing porosity, which affects many functional device properties, is non-trivial. Computed tomography (CT) is a quick, versatile, and non-destructive way to gain 3D structural information, yet various CT technologies, such as benchtop, preclinical and clinical systems, all have different capabilities. As system capabilities determine the structural information that can be obtained, seamless monitoring of key device features through all stages of clinical translation must be engineered intentionally. Therefore, in this study we tested feasibility of obtaining structural information in pre-clinical systems and high-resolution micro-CT (μCT) under physiological conditions. To overcome the low CT contrast of polymers in hydrated environments, radiopaque nanoparticle contrast agent was incorporated into porous devices. The size of resolved features in porous structures is highly dependent on the resolution (voxel size) of the scan. As the voxel size of the CT scan increased (lower resolution) from 5 to 50 μm, the measured pore size was overestimated, and percentage porosity was underestimated by nearly 50%. With the homogeneous introduction of nanoparticles, changes to device structure could be quantified in the hydrated state, including at high-resolution. Biopolymers had significant structural changes post-hydration, including a mean increase of 130% in pore wall thickness that could potentially impact biological response. By incorporating imaging capabilities into polymeric devices, CT can be a facile way to monitor devices from initial design stages through to clinical translation.

A Preclinical Trial Protocol Using an Ovine Model to Assess Scaffold Implant Biomaterials for Repair of Critical-Sized Mandibular Defects.

The present work describes a preclinical trial (in silico, in vivo and in vitro) protocol to assess the biomechanical performance and osteogenic capability of 3D-printed polymeric scaffolds implants used to repair partial defects in a sheep mandible. The protocol spans multiple steps of the medical device development pipeline, including initial concept design of the scaffold implant, digital twin in silico finite element modeling, manufacturing of the device prototype, in vivo device implantation, and in vitro laboratory mechanical testing. First, a patient-specific one-body scaffold implant used for reconstructing a critical-sized defect along the lower border of the sheep mandible ramus was designed using on computed-tomographic (CT) imagery and computer-aided design software. Next, the biomechanical performance of the implant was predicted numerically by simulating physiological load conditions in a digital twin in silico finite element model of the sheep mandible. This allowed for possible redesigning of the implant prior to commencing in vivo experimentation. Then, two types of polymeric biomaterials were used to manufacture the mandibular scaffold implants: poly ether ether ketone (PEEK) and poly ether ketone (PEK) printed with fused deposition modeling (FDM) and selective laser sintering (SLS), respectively. Then, after being implanted for 13 weeks in vivo, the implant and surrounding bone tissue was harvested and microCT scanned to visualize and quantify neo-tissue formation in the porous space of the scaffold. Finally, the implant and local bone tissue was assessed by in vitro laboratory mechanical testing to quantify the osteointegration. The protocol consists of six component procedures: (i) scaffold design and finite element analysis to predict its biomechanical response, (ii) scaffold fabrication with FDM and SLS 3D printing, (iii) surface treatment of the scaffold with plasma immersion ion implantation (PIII) techniques, (iv) ovine mandibular implantation, (v) postoperative sheep recovery, euthanasia, and harvesting of the scaffold and surrounding host bone, microCT scanning, and (vi) in vitro laboratory mechanical tests of the harvested scaffolds. The results of microCT imagery and 3-point mechanical bend testing demonstrate that PIII-SLS-PEK is a promising biomaterial for the manufacturing of scaffold implants to enhance the bone-scaffold contact and bone ingrowth in porous scaffold implants. MicroCT images of the harvested implant and surrounding bone tissue showed encouraging new bone growth at the scaffold-bone interface and inside the porous network of the lattice structure of the SLS-PEK scaffolds.

In vivo micro-computed tomography evaluation of radiopaque, polymeric device degradation in normal and inflammatory environments

Polymeric biomedical implants are an important clinical tool, but degradation remains difficult to determine post-implantation. Computed tomography (CT) could be a powerful tool for device monitoring, but polymers require incorporation of radiopaque contrast agents to be distinguishable from tissue. In addition, immune response to radiopaque devices must be characterized as it modulates device function. Radiopaque devices and films were produced by incorporating 0–20 wt% TaOx nanoparticles into polymers: polycaprolactone (PCL) and poly(lactide-co-glycolide) (PLGA). In vitro inflammatory responses of mouse bone marrow-derived macrophages to polymer matrix incorporating TaOx nanoparticles was determined by monitoring cytokine secretion. Nanoparticle addition stimulated a slight inflammatory reaction, increasing TNFα secretion, mediated by changes in polymer matrix properties. Subsequently, devices (PLGA 50:50 + 20 wt% TaOx) were implanted subcutaneously in a mouse model of chronic inflammation, that featured a sustained increase in inflammatory response local to the implant site over 12 weeks. No changes to device degradation rates or foreign body response were noted between a normal and chronically stimulated inflammatory environment. Serial CT device monitoring post-implantation provided a detailed timeline of device collapse, with no rapid, spontaneous release of nanoparticles that occluded matrix visualization. Importantly, repeat CT sessions did not ablate the immune system or alter degradation kinetics. Thus, polymer devices incorporating radiopaque nanoparticles can be used for in situ monitoring and be readily combined with other medical imaging techniques, for a dynamic view biomaterial and tissue interactions. Statement of significanceA growing number of implantable devices are in use in the clinic, exposing patients to inherent risks of implant movement, collapse, and infection. The ability to monitor implanted devices would enable faster diagnosis of failure and open the door for personalized rehabilitation therapies – both of which could vastly improve patient outcomes. Unfortunately, polymeric materials which make up most biomedical devices are not radiologically distinguishable from tissue post-implantation. The introduction of radiopaque nanoparticles into polymers allows for serial monitoring via computed tomography, without affecting device degradation. Here we demonstrate for the first time that nanoparticles do not undergo burst release from devices post-implantation and that inflammatory responses – a key determinant of device function in vivo – are also unaffected by nanoparticle addition.

Patient-specific implants made of 3D printed bioresorbable polymers at the point-of-care: material, technology, and scope of surgical application

BackgroundBioresorbable patient-specific additive-manufactured bone grafts, meshes, and plates are emerging as a promising alternative that can overcome the challenges associated with conventional off-the-shelf implants. The fabrication of patient-specific implants (PSIs) directly at the point-of-care (POC), such as hospitals, clinics, and surgical centers, allows for more flexible, faster, and more efficient processes, reducing the need for outsourcing to external manufacturers. We want to emphasize the potential advantages of producing bioresorbable polymer implants for cranio-maxillofacial surgery at the POC by highlighting its surgical applications, benefits, and limitations.MethodsThis study describes the workflow of designing and fabricating degradable polymeric PSIs using three-dimensional (3D) printing technology. The cortical bone was segmented from the patient’s computed tomography data using Materialise Mimics software, and the PSIs were designed created using Geomagic Freeform and nTopology software. The implants were finally printed via Arburg Plastic Freeforming (APF) of medical-grade poly (L-lactide-co-D, L-lactide) with 30% β-tricalcium phosphate and evaluated for fit.Results3D printed implants using APF technology showed surfaces with highly uniform and well-connected droplets with minimal gap formation between the printed paths. For the plates and meshes, a wall thickness down to 0.8 mm could be achieved. In this study, we successfully printed plates for osteosynthesis, implants for orbital floor fractures, meshes for alveolar bone regeneration, and bone scaffolds with interconnected channels.ConclusionsThis study shows the feasibility of using 3D printing to create degradable polymeric PSIs seamlessly integrated into virtual surgical planning workflows. Implementing POC 3D printing of biodegradable PSI can potentially improve therapeutic outcomes, but regulatory compliance must be addressed.

Hybrid Coatings Based on Polyvinylpyrrolidone/Polyethylene Glycol Enriched with Collagen and Hydroxyapatite: Incubation Studies and Evaluation of Mechanical and Physiochemical Properties.

Coating materials offers an intriguing solution for imparting inert implants with additional bioactive characteristics without changing underlying parameters such as mechanical strength. Metallic implants like endoprostheses or polymeric implants can be coated with a thin layer of bioactive film capable of stimulating bone-forming cells to proliferate or release a drug. However, irrespective of the final implantation site of such a coating biomaterial, it is necessary to conduct detailed mechanical and physicochemical in vitro analyses to determine its likely behavior under biological conditions. In this study, polymeric and composite coatings with hydroxyapatite obtained under UV light underwent incubation tests in four different artificial biological fluids: simulated body fluid (SBF), artificial saliva, Ringer's fluid, and water (as the reference fluid). The potentiometric and conductometric properties, sorption capacity, and degradation rate of the coatings were examined. Furthermore, their hardness, modulus of elasticity, and deformation were determined. It was demonstrated that the coatings remained stable in SBF liquid at a pH value of around 7.4. In artificial saliva, the greatest degradation of the polymer matrix (ranging between 36.19% and 39.79%) and chipping of hydroxyapatite in the composite coatings were observed. Additionally, the effect of ceramics on sorption capacity was determined, with lower capacity noted with higher HA additions. Moreover, the evaluation of surface morphology supported by elemental microanalysis confirmed the appearance of new apatite layers on the surface as a result of incubation in SBF. Ceramics also influenced mechanical aspects, increasing hardness and modulus of elasticity. For the polymer coatings, the value was 11.48 ± 0.61, while for the composite coating with 15% ceramics, it increased more than eightfold to a value of 93.31 ± 11.18 N/mm2. Based on the conducted studies, the effect of ceramics on the physicochemical as well as mechanical properties of the materials was determined, and their behavior in various biological fluids was evaluated. However, further studies, especially cytotoxicity analyses, are required to determine the potential use of the coatings as biomaterials.

An Updated Comprehensive Review on Novel Drug Delivery Systems (NDDS) In the Pharmaceuticals

The field of pharmaceutical sciences has witnessed a paradigm shift with the advent of Novel Drug Delivery Systems (NDDS), which aim to enhance therapeutic efficacy, reduce side effects, and improve patient compliance. This comprehensive review explores the latest advancements and innovations in NDDS, encompassing a diverse range of delivery platforms and strategies.(NDDs are transforming the landscape of pharmaceutical treatment, offering unparalleled potential for enhanced therapeutic efficacy, improved bioavailability, controlled release, targeted delivery, and enhanced stability. This comprehensive review explores the diverse landscape of NDDS, highlighting recent advancements and addressing key challenges. Prominent NDDS include liposomes, nanoparticles, micelles, polymeric drug conjugates, monoclonal antibodies, implants, and patches. Each system possesses unique properties and applications, tailored to specific drugs and therapeutic needs. Recent breakthroughs in targeted nanocarriers, gene therapy vectors, and 3D-printed personalized dosage forms are pushing the boundaries of innovation. The main highlights of the present review firstly the basics on NDDs, the several approaches of nano drug carriers for the drug delivery with their preparation methods and example. The middle version of review discuss the recent advancements techniques in the preparation of NDDs carriers and lastly the marketed formulation of particular drug carrier.

Radiopacity Enhancements in Polymeric Implant Biomaterials: A Comprehensive Literature Review.

Polymers as biomaterials possess favorable properties, which include corrosion resistance, light weight, biocompatibility, ease of processing, low cost, and an ability to be easily tailored to meet specific applications. However, their inherent low X-ray attenuation, resulting from the low atomic numbers of their constituent elements, i.e., hydrogen (1), carbon (6), nitrogen (7), and oxygen (8), makes them difficult to visualize radiographically. Imparting radiopacity to radiolucent polymeric implants is necessary to enable noninvasive evaluation of implantable medical devices using conventional imaging methods. Numerous studies have undertaken this by blending various polymers with contrast agents consisting of heavy elements. The selection of an appropriate contrast agent is important, primarily to ensure that it does not cause detrimental effects to the relevant mechanical and physical properties of the polymer depending upon the intended application. Furthermore, its biocompatibility with adjacent tissues and its excretion from the body require thorough evaluation. We aimed to summarize the current knowledge on contrast agents incorporated into synthetic polymers in the context of implantable medical devices. While a single review was found that discussed radiopacity in polymeric biomaterials, the publication is outdated and does not address contemporary polymers employed in implant applications. Our review provides an up-to-date overview of contrast agents incorporated into synthetic medical polymers, encompassing both temporary and permanent implants. We expect that our results will significantly inform and guide the strategic selection of contrast agents, considering the specific requirements of implantable polymeric medical devices.

Long-term in vivo dissolution of thermo- and pH-responsive, 19F magnetic resonance-traceable and injectable polymer implants.

19F magnetic resonance (19F MR) tracers stand out for their wide range of applications in experimental and clinical medicine, as they can be precisely located in living tissues with negligible fluorine background. This contribution demonstrates the long-term dissolution of multiresponsive fluorinated implants designed for prolonged release. Implants were detected for 14 (intramuscular injection) and 20 (subcutaneous injection) months by 19F MR at 4.7 T, showing favorable MR relaxation times, biochemical stability, biological compatibility and slow, long-term dissolution. Thus, polymeric implants may become a platform for long-term local theranostics.